A textile antenna with an electric bandgap (EBG) structure for body surface wave enhancement is proposed. The proposed antenna is composed of a centre-fed circular patch to generate the TM₀₁ mode and an EBG structure near the patch to guide the TM wave along the horizontal surface (θ = 90°). Considering the wearability, the antenna has been fabricated using only textile materials such as conductive textiles, conductive thread, and a leather substrate, and has an enhanced radiated field along the surface direction in the 5.8 GHz industrial, scientific, and medical (ISM) band for on-body communication. The proposed antenna has a diameter of 1.98λ ₀ and a thickness of 0.058λ ₀ at 5.8 GHz.

A modulatable electromagnetically induced transparency (EIT) is achieved using a slotted circle ring structure. The circle ring structure is used to induce a polarisation-independence resonance with a low Q factor, while the slot is etched to obtain a polarisation-dependence resonance with a high Q factor. The EIT effect is obtained when the two resonances have nearby resonant frequencies but with different Q factors. As both resonant modes are excited by the external field independently, different coupling strength is achieved simply by adjusting the polarisation angle. Then the transmission of EIT is successfully modulated. The design concept is well validated both by simulation and measurement.

A compact two-layer frequency-selective surface is presented to design circular polarisers for broadband applications. By optimising the parameters of the semi-circle metal strip element, an excellent simulated bandwidth of axial ratio (AR) (lower than 3 dB) is achieved from 10.02 to 11.09 GHz, while the amplitude of the transmission coefficient is higher than 0.8. Furthermore, the polariser unit cell is less sensitive to the range of oblique incidence angles. To verify the proposed design, an X-band circular polariser prototype is fabricated and measured. The results show that excellent AR performance can be achieved; the measured AR of the transmission wave is lower than 3 dB in the band from 9 to 12 GHz.

A new method for connecting transmission lines is presented without using rigid connectors in order to implement a fully textile interconnecting system appropriate for signal transmission in wearable applications. This method is applied to textile striplines and named ‘complementary overlap’. The proposed method is examined from 1 to 6 GHz covering the frequency bands of the target applications: ISM (WLAN, Bluetooth, ZigBee etc.) and L-band (GPS).

The first dual-band printed monopole antenna for wireless M-Bus and M2M applications with operation in the VHF and lower UHF bands is presented. The antenna operates at 169 and 433 MHz. The miniaturisation of the proposed compact antenna is based on a double-sided meandering structure offering an easily controlled large frequency ratio. The antenna provides high total efficiency and gain in both bands. Measured and simulated results are reported.

The specific differential attenuation caused by large raindrops and a special form of melting hail is computed and studied. Raindrops of smoothed conical shapes and hailstones modelled by an ice sphere surrounded by a water torus are considered. For the former, scattering computation is carried out by the T-matrix method, while the higher-order method of moments in the surface integral equation formulation is used for the latter. Results show a much higher specific differential attenuation factor for hail particles, with the smallest hail showing values similar to the largest raindrops. This can explain the higher than expected differential attenuation observed by C-band radars in intense storms as reported in some previous studies. Results also show that the melting hail particles exhibit higher specific differential phase factor than large raindrops, but have similar differential reflectivity.

A compact and low-loss MEMS-based phase shifter is proposed for microwave/millimetre-wave phased array antenna systems. The proposed phase shifter is an alumina-based CPW line, loaded with a variable series capacitor. The phase shifter uses an electromagnetic MEMS actuator to change the capacitor value. A simple three-mask surface micromachining process has been developed for device fabrication. The measurements at 26 GHz show a phase shift of 20°. The overall size of the phase shifter (including the actuator) is 0.5 × 1.5 mm. The measured average insertion loss is 0.75 dB with a variation of 0.4 dB for different phase shifts across the band from 24.5 to 26.5 GHz.

Pleural effusion (PE) is the accumulation of fluids around the lungs due to various diseases, such as cancer, liver and heart failure. Given the fact that fluid provides a high contrast in terms of dielectric constant at microwave frequencies, a radar-based microwave imaging system is proposed to utilise that change in properties for the early detection of PE. The system uses a wideband slot-loaded loop antenna to scan the torso, a portable vector network analyser for signal generation and recording, and a laptop for signal processing and image formation using a frequency-based imaging algorithm. The utilised antenna is designed to have a compact size (in wavelengths) of 0.23 × 0.23 that is one-third the size of recent designs. By using proper slots in a conventional slot-loaded loop and adding a staircase-shaped patch to the loop's perimeter, the antenna achieves a fractional bandwidth of 50% (0.72–1.19 GHz), and a peak gain of 4.9 dBi. The practicality of the proposed system is successfully tested by detecting a small amount of fluid (3 mL) around the lungs of a realistic life-size torso phantom.

A quarter-wavelength-thick unprinted dielectric slab is placed above a slot antenna to achieve high gain with a large bandwidth. By optimally truncating the high-permittivity superstrate to a small area of 2.25λ₀ ², 8–10 dB enhancement in the directivity of the slot is achieved over a 3 dB directivity bandwidth of 16–18%. A prototype antenna was fabricated and tested at 11.5 GHz. Its measured peak gain is 16.95 dBi and the 3 dB gain bandwidth is 16.25%. The proposed antenna is simple and, more importantly, has a lower profile with a total height of 0.593λ ₀.

A new topology of a transconductor suitable for the implementation of transconductance-C (Gm-C) integrators with time constants of tens of seconds using sub-pF capacitors is introduced. The proposed circuit relies on a cascode stage driven backwards, i.e. the input signal is applied to the cascode output node. The key point is taking advantage of the high impedance of the cascode to impose high attenuation to the input signal and to establish transconductances in the order of fA/V. The concept is demonstrated at the simulation level by realising a Gm-C integrator with a time constant of 100 s. The integrator comprises a 0.7 pA/V transconductor and an 800 fF capacitor at its output.

A novel double-tuned radio-frequency (RF) receiver coil for use in magnetic resonance imaging (MRI) systems has been demonstrated based on a birdcage-type circuit. The receiver coil utilises the end-ring current as well as the leg current of the birdcage-type circuit to detect the nuclear magnetic resonance (NMR) signals of different elements simultaneously. It was designed to detect the NMR signals of both ¹H and ³¹P elements in a 4.7 T MRI system. The coil showed an excellent frequency response and provided clear magnetic resonance images of a Na₂HPO₄ phantom when used with the 4.7 T MRI system.

A new edge localisation technique for step edges in images with signal-dependent Rician noise in MRI is proposed. Dependent noise can not only affect the detection of true edges in an image but also their position. Inaccurate localisation of an edge can lead to insufficient segmentation and reduce the overall accuracy of any edge detection method. The proposed technique uses higher-order moments of the noise function to determine the correction factor for localisation and thus reduce the overall mean square error for true edge localisation due to noise. The proposed technique offers significant improvement in edge localisation for an image as compared with Canny and Sobel methods.

A novel method of signal averaging within the wavelet transform time–frequency plane is presented. This running wavelet archetype technique uses the inherent scale-dependent periodicity of the wavelet function within the averaging process, thus removing the requirement for the identification of fiducial points which is often the main cause of errors in traditional methods. The technique is illustrated using a synthetic signal and in its application to the detection of a cardiac pulse component in a noisy photoplethysmographic signal.

A digital excess loop delay (ELD) compensation suited for high speed delta–sigma modulators is presented. Its operation is based on computing the digital outputs for all the possible values of the ELD compensation feedback and performing the selection in the digital domain. The proposed technique also uses a novel comparator sharing approach which minimises the number of comparators needed in the quantiser.

A highly linear current-controlled delay unit (CCDU) is presented. The proposed design linearly delays an input clock edge against an applied input current. The topology features a directly proportional input/output relation compared with an inversely proportional one in the traditional current-starved inverter (CSI). The proposed CCDU features a THD of only 0.15% compared with 22.6% in a conventional CSI over the same input dynamic current range of 180 nA. The proposed CCDU is implemented in 65 nm CMOS and consumes only 0.74 μW. An analogue-time-digital ADC is simulated using the proposed CCDU as a front-end block, achieving a resolution (ENOB) of 9.07 bits. Monte Carlo analysis confirms the linearity of the proposed CCDU under mismatch and process variation.

The possibility to see route-to-chaos scenarios in common analogue filtering structures known as state variable filters is described. It is shown that strange attractors characterised by a fractal geometrical dimension can be observed in these naturally linear network structures if integrators are supposed to be exclusive nonlinear two-ports.

A digital-domain dual-calibration for single-ended successive approximation register analogue-to-digital converters (SAR ADCs) is presented. The dual-calibration combines digital error correction with capacitor mismatch calibration to compensate the decision errors and improve capacitor matching. Simulation results show that the proposed digital-domain dual-calibration technique can significantly improve signal-to-noise-and-distortion and spurious-free dynamic range for the single-ended SAR ADC.

Interpolation plays a key role in the fractional motion estimation (FME) of video encoders. A hardware implementation of a FME interpolator is presented for high efficiency video coding. The proposed interpolator processes each 8 × 8 block in a pipelined manner with efficiently shared finite impulse response filters to improve the performance while reducing gate counts. Implementation results show that the proposed design leads to fewer execution cycles with a small silicon area compared with conventional designs.

An energy-saving strategy for application-centric networks is proposed. A new architecture for energy-efficient Ethernet that meets the quality of service requirements for different classes of service is studied.

Families of sequences with low off-peak autocorrelation and low cross-correlation are highly valued in spread-spectrum communication. Digital watermarking has an equal need for diverse families of orthogonal multi-dimensional (nD) arrays, where each array has optimal correlation properties. In this reported work, a 1D discrete projection method is used to construct new families of nD orthogonal arrays of size pⁿ , with p a 4k − 1 prime. Finite field algebra and Hadamard matrices are applied to analyse these arrays. The periodic autocorrelation of each array is ‘perfect’ (p ² − 1 peak value, with −1 off-peak for p × p arrays). The cross-correlation between any pair of the p members of each 2D family has the lowest possible values, 0 or ±p. The arrays can be synthesised for arbitrarily large p and outperform Kasami sequences. The alphabet values for these optimal arrays can be roots of unity or signed integers. The aperiodic autocorrelation of the p × p arrays can attain a merit factor of above 3 at shift (p/4, p/4), consistent with Golay's conjecture in 1D.

The joint effects of feedback delay, limited feedback and channel estimation errors on the secrecy performance of a multiple-input–single-output (MISO) system employing transmit beamforming against passive eavesdropping are investigated. Closed-form expressions of the effective secrecy throughput which characterise the average rate of achieving reliable and secure transmissions are derived. Simulation results verify the theoretical analysis and show that different from feedback delay and limited feedback which degrade performance, imperfect channel estimation may not always harm the secrecy throughput. Furthermore, it is interesting to find that there exists an optimal transmit signal-to-noise ratio (SNR) for achieving the maximal secrecy throughput and channel state information imperfections will increase the optimal value of the transmit SNR.

In previous work, the present authors discovered the resonant splitting phenomenon of a plasmonic perforated gold film (PGF), as the incident light comes in the polar angle. However, in reality, the light through the imaging lens could be incident on the PGF not only in the polar angle but also in the azimuth angle. The transmission of a PGF against the incident light is analysed in both polar and azimuth angles in spherical coordinates. To mimic the incidence through the lens, a PGF sample is rotated by simultaneously varying both types of angles as normal incidence arrives. For the measurement, the sample has been fabricated with a PGF on a semi-insulating gallium arsenide (GaAs) substrate. The measured transmission spectra show both resonant splitting and merging under TM and TE polarisations as the azimuth angle is increased. Results drawn from this work will pave the way to fully understanding the interaction between the imaging lens and the plasmonic structure (PGF).

A levitation configuration is reported wherein diamagnetic levitation, weight compensated diamagnetic levitation and diamagnetically stabilised levitation are combined. The configuration allows the simultaneous inline triple levitation of three different bodies without the need of energy input or feedback control. The proposed levitation setup could find application in sensitive multi-range seismometers or accelerometers wherein levitating seismic bodies with different masses and resonance behaviour are needed.

A novel and compact ultra-wideband (UWB) bandpass filter (BPF) based on the broadband balun mechanism is proposed. The proposed structure is made up of two back-to-back open circuited meandered microstrip lines on the top plane coupled in a broadside fashion with a short circuited co-planar waveguide in the ground. This configuration gives rise to a smooth UWB passband with an insertion loss of <0.19 dB in simulation and two transmission zeros at the lower and upper passband edges which provide sharp selectivity. To confirm the theory a prototype is fabricated and its measured response is found to be in close agreement with the simulated response. The proposed structure is very small in size measuring only 14.6 × 7.3 mm².

A current generator for a broadband 6-bit active phase shifter (PS) with low RMS phase error and low RMS gain error using 0.18 μm BiCMOS technology is presented. The ratio of two output currents of the current generator determines the phase shift. In the proposed current generator, the two output currents are controlled independently, which makes it possible that the ratio of the two output currents can be accurately approaching the desired value. The control scheme for 6-bit phase generation is set such that the sum of the two output currents is constant for all phase states and results in a constant gain. With the proposed current generator, the 6-bit active PS obtains a RMS phase error less than 2.5° and a RMS gain error less than 0.55 dB at 5–20 GHz.

A miniaturised dual-band bandpass filter (DB-BPF) centred at 2.45/5.70 GHz using novel symmetric double-spiral resonators is proposed. The measured and simulated results of the proposed DB-BPF are in good agreement with each other except for a slight frequency shift downwards in the measurement. According to the measurements, the measured 3 dB bandwidths are 6.53% (2.35–2.51 GHz) at 2.45 GHz and 4.2% (5.61–5.85 GHz) at 5.70 GHz; the insertion losses including the loss from SMA connectors are <0.8/1.2 dB and the isolation between these two passbands is better than 20 dB from 2.54 to 5.59 GHz. The circuit area of the fabricated prototype is very compact, being only 7.7 × 9.4 mm.

The design of a 4-channel 35 Gbit/s parallel laser diode driver (LDD) using 65 nm CMOS technology is presented. The LDD driver consists of an input buffer stage, a pre-amplifier stage and an output driver stage. The three-stage cascaded amplifiers constitute the pre-amplifier stage, and an active feedback technique is employed to expand bandwidth without consuming a large area. The output driver stage introduces RC negative feedback and inductive shunt peaking techniques to broaden the bandwidth. Measurement results show that the operating rate of each channel is up to 35 Gbit/s and the power consumption per data rate is only 4.4 mW/(Gbit/s).

A 2.5 Gbit/s burst-mode receiver for passive optical network (PON) systems with both a fast receiver settling time of 24.1 ns and a high tolerance to consecutive identical digits (CIDs) of 629 bits, by using a preamplifier with a unique peak-detecting automatic gain control function is developed. It is broadly applicable to the time- and wavelength-division multiplexed-PON systems of NG-PON2, which need a wide dynamic range suitable for a 64-way split and a transmission distance exceeding 40 km.

A component-efficient design for optical multi/demultiplexers (OMDPXs) relying on 2 × 2 switch elements (SEs) with a bidirectional property is described for the first time. First, the observation is made that some 2 × 1 or 1 × 2 SEs used in conventional OMDPXs have been implemented with part of a 2 × 2 SE. A novel design of OMDPXs fully utilising the connection capability of 2 × 2 SEs is presented. The SE count in the design becomes virtually half of that in the conventional design because a 2 × 2 SE is equivalent to a pair of 2 × 1 and/or 1 × 2 SEs. Other basic characteristics such as insertion loss and cross-talk are also approximated. Finally, the design provides an N × N optical switch composed of N(N − 1)/2 2 × 2 SEs instead of N ² for conventional optical cross-bar switches, keeping the strictly non-blocking capability unlike N-stage planar switches, which are rearrangeably non-blocking while composed of the same number of SEs as the design.

A quality of transmission (QoT)-aware adaptive adjustment scheme of optical path transmission performance under software control is proposed. First, a mathematical model of optical path transmission performance adjustment is established. Based on it, a new device link quality equaliser (LQE) is built. Second, using a centralised controller, the LQE introduces devices with different compensation abilities into the optical path. Therefore, it becomes an all-optical mode node or an optical–electrical–optical (O/E/O) mode node adaptively. Then an adaptive and elastic adjustment can be conducted on the transmission performance of the optical path. Finally, an experiment is presented to show the feasibility and effectiveness of the proposed scheme.

The effect of six different infill patterns on the print quality of a dispenser-printed silver ink on Kapton polyimide film is investigated. The results indicate that improved and more complex printed electronic structures can be produced due to the improvement in print homogeneity. Dispenser printing is a rapid manufacturing process using direct write technology that can be used to deposit a broad range of inks onto substrates irrespective of their surface geometry. Standard three-dimensional printer infill patterns known as line, rectilinear, concentric, honeycomb, Hilbert curve and Archimedean chords were tested at densities of 30, 50 and 70%. The prints were timed allowing comparison of print speed. After curing, the coverage was checked and the surface roughness (R_a ) was measured. The results showed that only the rectilinear infill pattern at 50% density print, and the rectilinear and honeycomb infill patterns at 70% density achieved 100% coverage. The 50% rectilinear print was the fastest of the 100% coverage prints, and the 70% honeycomb print had the lowest surface roughness. The rectilinear pattern at 50% is recommended if there is only one layer to print. The honeycomb pattern is recommended for multilayer prints, where surface roughness is the key.

A compositionally step-graded (CSG) InGaN barrier is designed for the active region of c-plane blue light-emitting diodes (LEDs). High external quantum efficiencies of 45, 42, 39 and 36% are achieved at current densities of 100, 200, 300 and 400 A/cm², respectively. Compared with GaN barrier devices, LEDs with CSG InGaN barriers showed higher power, lower operating voltage and smaller wavelength blueshift, compared with GaN barrier LEDs. Owing to the low-voltage performance, higher wall-plug efficiency can be achieved for blue LEDs with CSG InGaN barriers.

X-ray power supplies must operate under a wide variety of conditions. In fluoroscopy mode, they must transfer from 20 W to 1.2 kW, while in radiography mode they reach up to 100 kW. Input voltage range is also wide: from 400 to 750 V. Designers must achieve full power with lower input voltage, accepting important drops in efficiency under other circumstances. A two-inverter multilevel resonant topology is proposed to address these problems. Adapting the resonant elements, the resulting power stage is versatile enough to minimise the resonant current for both radiography and fluoroscopy. Input voltage fluctuations are compensated by the inverter operations.

A novel zero current soft-switching (ZCS) pulse-width modulation (PWM) bidirectional dc–dc converter (BDC) with non-inverting polarity multi-mode voltage regulations is presented. In the proposed BDC, all the power devices commutate in ZCS with the aid of single-auxiliary switch-based edge-resonant cells; accordingly the switching power losses can be minimised. The effectiveness of the proposed BDC and its steady-state characteristics are verified in experiments with a 500 W–50 kHz prototype.

Sequence sets with good correlation properties lie at the core of many communication and radar applications. A new approach to the design of sequence sets is proposed. The ideal correlation matrix is defined, and the design problem is formulated as a power spectral density (PSD) fitting problem. In this manner, a simpler minimisation problem is obtained, and an iterative method is applied to solve it. Simulation results demonstrate that the performance of the proposed approach is superior to that of the previous state-of-the-art algorithm.

In geosynchronous (GEO) synthetic aperture radar (SAR), the satellite track is curvilinear and the typical assumption of ‘stop-and-go’ breaks down due to the increase of orbit altitude. Thus, standard imaging algorithms based on the conventional hyperbolic range equation (CHRE) become inadequate. A four-order range equation taking the ‘stop-and-go’ errors into consideration is adopted to improve the accuracy in the approximation of the range history for GEO SAR. Then, an accurate two-dimensional spectrum is analytically deduced under the curved trajectory model, and a modified nonlinear chirp scaling (NLCS) algorithm is proposed according to this new spectrum. Simulation results validate that the proposed algorithm has better performance than the CHRE-based NLCS algorithm in the GEO cases.

A ground-based (GB) synthetic aperture radar (SAR) system is proposed for soil surface roughness discrimination at the C-band. By using this GB-SAR system, the multi-angular SAR measurement is realised at different resolution cell sizes. The specific levels of surface roughness are set deliberately to analyse the roughness contribution on the multi-angular SAR signature in a controlled experimental condition. Based on the GB-SAR measurement, the effect of incidence angle on SAR sensitivity is studied under two resolution cell sizes for retrieving soil surface roughness. The results show that, the using the GB-SAR system, the high incidence angle configuration (e.g. > 40°) is optimal to discriminate surface roughness, which is more significant at small resolution cell sizes (e.g. 30 cm). This study indicates the effectivity of the GB-SAR system to validate the SAR backscattering mechanisms.

In high-resolution spaceborne synthetic aperture radar (SAR), the hyperbolic range equation assumption fails to precisely describe the range history; thus, the traditional resolution analysis used for a spaceborne SAR design is imprecise. A curved orbit geometrical model based on the modified equivalent squint range model is graphically presented by vector notation. According to the model, the vectorial calculation of resolution is analytically presented, based on the gradient method. Additionally, a physical model is introduced to derive the effective integration time, which is quite difficult to derive due to the three-dimensional curved orbit. Simulation results are presented to validate the proposed method.

An AlGaN/GaN metal–insulator–semiconductor high electron mobility transistor (MIS-HEMT) on Si substrate was obtained with 18 nm silicon nitride (Si₃N₄) grown by low-pressure chemical vapour deposition (LPCVD) as the gate insulator. The D-mode MIS-HEMT shows a high I _dss of 16.8 A at V _g = 3 V, a high breakdown voltage (BV) of 600 V and a low-specific on-resistance of 2.3 mΩ·cm². The power device figure of merit (FOM = BV²/R _on,sp) is calculated as 157 MW·cm⁻². The good insulation effects of LPCVD-Si₃N₄ were also demonstrated by the low gate leakage current of 154 nA at V _ds = 600 V and V _gs = −14 V. Furthermore, an E-mode device was realised by a low-voltage silicon metal–oxide-semiconductor field-effect transistor in series; the V _th was determined to be 2.6 V. The high I _dss, low-specific on-resistance, high BV and positive V _th show the potential and advantages of GaN MIS-HEMTs for power switching applications.

An indium gallium arsenide (InGaAs) dual-channel metal–oxide-semiconductor field-effect transistor (DCMOSFET) for high-frequency small signal applications is proposed. The gate electrode of the proposed device is placed in a trench to create two n-channels in the p-base. The simultaneous conduction of two channels provides significant improvement in all the performance parameters. Two-dimensional (2D) simulations are performed to evaluate and compare the performance of the DCMOSFET with that of the conventional MOSFET. At 60 nm gate length, the proposed device provides 92% higher drain current, nearly two times improvement in peak transconductance, 50% increase in cutoff frequency and 74% higher maximum frequency of oscillation with better control over the short channel effects as compared with the conventional device.

To study the electron transport properties in high electron mobility transistors (HEMTs), it is essential to have a correct estimation for electron density distribution. The introduction of back barriers in GaN-based HEMTs leads to a modified profile of a two-dimensional (2D) electron wave function, which can no longer be described by the standard Fang-Howard model. To address this change, a numerical model is developed for the wave function calculation based on the variational Hartree method. An electron density profile in the GaN channel with AlGaN top and back barriers has been simulated. The results are in good agreement with those obtained from self-consistent Poisson-Schrödinger simulation. The centroid of the 2D electron gas is also calculated as a function of the Al composition in the AlGaN back barrier.

A high energy-efficiency K-band on–off keying (OOK) transmitter in tsmc™ 90 nm CMOS technology is presented. The transmitter consists of a wideband voltage control oscillator (VCO), a frequency doubler and a switch-type power amplifier with a chip area of 0.6 × 0.92 mm². The VCO adopts a parasitic capacitance reduction technique to enhance the tuning range to 20.5%. The designed transmitter achieves an output power of 3 dBm with a 500 Mbit/s data rate from 19 to 23.1 GHz at 22.3 mW power consumption. The correspondent energy-efficiency is 44 pJ/bit.

A wideband voltage-controlled oscillator (VCO) covering 2.24–4.95 GHz for multi-standard wireless applications is presented. Realised in TSMC 180 nm RFCMOS process, the VCO provides a phase noise <–124.2 dBc/Hz at a 1 MHz offset in the whole frequency range, while drawing 10 and 18 mA at 4.95and 2.24 GHz from a 1.8 V supply, respectively. The achieved tuning range is 75% and the core chip area is 0.51 mm².

A voltage–current (V–I) converter-based voltage-controlled oscillator (VCO) is adapted to generate multiple-phase clocks for clock and data recovery for a display driver IC. The proposed V–I converter changed the second-order current equation of the VCO to a first-order current equation of the VCO, to achieve a wide operating frequency range, a linear gain (K _VCO) within a wide control voltage, low power, and a small area without any extra circuits, such as a low-to-full amplifier. Owing to the V–I converter, K _VCO is changed from 8.43 to 2.05 MHz/mV with a wider V _ctrl range, and its tuning range is changed from 114 to 452 MHz with a linear gain characteristic. The proposed VCO is implemented in a 1P6M 1.8 V technology and is suitable for the phase-locked loop used in flat-panel display interfaces that operate from 0.3 to 2 Gbit/s.