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Volume 148
Issue 1
IEE Proceedings - Microwaves, Antennas and Propagation
Volume 148, Issue 1, February 2001
Volumes & issues:
Volume 148, Issue 1
February 2001
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- Author(s): R. Loison ; R. Gillard ; J. Citerne ; G. Piton ; H. Legay
- Source: IEE Proceedings - Microwaves, Antennas and Propagation, Volume 148, Issue 1, p. 1 –8
- DOI: 10.1049/ip-map:20010228
- Type: Article
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Modelling is presented of microstrip antenna arrays with an optimised 2D multi-resolution method of moment (MRMoM). A Chui-Haar 2D multi-resolution basis is used for the expansion of surface currents, and a pseudo-Galerkin scheme is introduced to speed up the algorithm. It is shown that, for large structures, the MRMoM generates sparse linear systems, which allows a significant reduction of CPU time and memory storage. The optimisation of a physical a priori criterion is presented. With this criterion, it is possible to predict which elements of the generalised impedance matrix can be neglected: thus for the first time the MoM matrix filling time is really reduced. The fast wavelet transform is also exploited for the computation of the non-negligible matrix elements. Theoretical results involving microstrip antenna arrays are presented and compared with experiments. - Author(s): G. Pelosi ; G. Toso ; C. Gennarelli
- Source: IEE Proceedings - Microwaves, Antennas and Propagation, Volume 148, Issue 1, p. 9 –14
- DOI: 10.1049/ip-map:20010217
- Type: Article
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The radiation of a vertical electric dipole over a thin dielectric slab is analysed. The problem can be decomposed into two simpler ones involving the radiation of the same dipole, first over a perfectly conducting plane, which has a trivial solution, and then over an impedance plane, for which the Green's function can be directly obtained from the corresponding scalar problem. To demonstrate the effectiveness of the solution for real structures of finite extension, the results are compared with those obtained by resorting to a moment method solution and to a physical optics technique. The proposed Green's function can be used to analyse the radiation of wire antennas in the presence of planar resistive structures. - Author(s): M. Zheng ; P. Gardener ; P.S. Hall ; Y. Hao ; Q. Chen ; V.F. Fusco
- Source: IEE Proceedings - Microwaves, Antennas and Propagation, Volume 148, Issue 1, p. 15 –20
- DOI: 10.1049/ip-map:20010221
- Type: Article
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The use of a cavity coupled to an active integrated antenna oscillator is described. The cavity increases the loaded Q factor of the oscillator, thus improving stability and reducing the phase noise. Cavity stabilisation of a microstrip patch and slot ring oscillators is described. In both cases, phase noise at a frequency offset of 10 kHz is reduced by the order of 20 dB. A first-order analysis based on measured and simulated cavity Q factors is shown to give similar results. A Van der Pol analysis of a two-element array of patch oscillators, with a single extended coupled cavity, indicates that the likelihood of mutual locking in an array which has oscillators with slightly different free running frequencies is enhanced albeit at the expense of increased start-up time. - Author(s): S.C. Gao ; L.W. Li ; T.S. Yeo ; M.S. Leong
- Source: IEE Proceedings - Microwaves, Antennas and Propagation, Volume 148, Issue 1, p. 21 –24
- DOI: 10.1049/ip-map:20010223
- Type: Article
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The design and experiments of a novel dual linearly polarised (LP) microstrip antenna array with a high isolation and low cross-polarisation levels are presented. The theoretical analysis is based on the finite-difference time-domain method and the multiport network model. The multifeed technique and the diagonal feeding are combined to realise the dual-polarised antenna elements. A single antenna element is designed and the experimental results show a good isolation between two polarisation ports. The dual LP elements are sequentially rotated to form the microstrip antenna array. A four-element dual LP array is also designed at 6.6 GHz and measured. Both theoretical and experimental results are presented and compared. The proposed array uses a single-layer structure so it is easy to fabricate and the cost is very low. It is also easy to extend the principle of present array to large-scale dual LP arrays and those of multilayered structures. - Author(s): R.G. Rojas and K.W. Lee
- Source: IEE Proceedings - Microwaves, Antennas and Propagation, Volume 148, Issue 1, p. 25 –28
- DOI: 10.1049/ip-map:20010222
- Type: Article
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A scheme for controlling the surface wave behaviour on printed planar antennas is presented. The approach is to add conducting strips both on top and, if necessary, the bottom of the substrate. The scheme is applied to a rectangular microstrip antenna with electrically thick (~0.1λd) substrate. An optimisation algorithm is employed to design the strip parameters in order to obtain the best performance of the antenna, namely, low side and back lobe levels and a main beam without ripples. The optimal design is then fabricated and tested. Measured results are presented to assess the validity of the proposed scheme. - Author(s): S. Rikte ; G. Kristensson ; M. Andersson
- Source: IEE Proceedings - Microwaves, Antennas and Propagation, Volume 148, Issue 1, p. 29 –36
- DOI: 10.1049/ip-map:20010215
- Type: Article
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A systematic analysis for solving the wave propagation problem in a general bianisotropic, stratified medium is presented. The method utilises the concept of propagators, and the representation of these operators is simplified by introducing the Cayley–Hamilton theorem. The propagators propagate the total tangential electric and magnetic fields in the slab and only outside the slab do the up- and down-going parts of the fields need to be identified. This procedure makes the physical interpretation of the theory intuitive. The reflection and the transmission dyadics for a general bianisotropic medium with an isotropic (vacuum) half-space on both sides of the slab are presented in a co-ordinate-independent dyadic notation, as well as the reflection dyadic for a bianisotropic slab with perfectly electric backing (PEC). In the latter case the current on the metal backing is also given. Some numerical computations that illustrate the algorithm are presented. - Author(s): Z.N. Chen and M.Y.W. Chia
- Source: IEE Proceedings - Microwaves, Antennas and Propagation, Volume 148, Issue 1, p. 37 –40
- DOI: 10.1049/ip-map:20010227
- Type: Article
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The paper demonstrates a new means of achieving a broad impedance bandwidth with a simple mechanical structure and low cross-polarisation levels for a suspended plate antenna with a co-axial probe-fed strip. The feeding-strip co-planar with the plate has a capacitive coupling with the plate, which effectively wipes out large inductance due to the long probe and gives rise to a broad impedance bandwidth. The narrow feeding structure avoids unwanted change of the current distribution at the plate surface and therefore, improves the polarisation performance to some degree. Furthermore, the co-planar feeding configuration simplifies the mechanical structure of the antenna. As examples, two rectangular suspended probe-fed strip single-layer plate antennas were made and examined experimentally. Measurements demonstrate good performances with broad impedance bandwidths up to 36%, stable radiation patterns with cross-polarisation levels of less than –17 dB, and gains of 4–5 dBi. - Author(s): K.L. Lau ; K.M. Luk ; K.F. Lee
- Source: IEE Proceedings - Microwaves, Antennas and Propagation, Volume 148, Issue 1, p. 41 –44
- DOI: 10.1049/ip-map:20010220
- Type: Article
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The design and measured results of a wideband antenna array of four U-slot rectangular patches are presented. The U-slot patches are proximity coupled by a microstrip feed line terminating with novel Π-shaped stubs. By using a foam layer of thickness t ~ 5.5 mm as the supporting substrate, an impedance bandwidth (SWR ≤ 2) of 27% ranging from 3.4 GHz to 4.5 GHz is achieved. It has an average gain of 13 dBi and a cross-polarisation of less than –20 dB. - Author(s): C. Oestges and D. Vanhoenacker-Janvier
- Source: IEE Proceedings - Microwaves, Antennas and Propagation, Volume 148, Issue 1, p. 45 –49
- DOI: 10.1049/ip-map:20010226
- Type: Article
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An original method for predicting the performance of upcoming stratospheric communication systems is presented. The prediction is based on a physical–statistical model of the built-up channel, used in combination with existing models of the tropospheric mechanisms. The physical nature of the approach allows the statistics of fade and BER to be obtained as a function of any input parameter, such as the size of the target area, the platform height or the area characteristics. Simulations provide, for example, values of BER achieved over a certain percentage of area during a given percentage of time, as a function of the ground range right below the platform. Various system procedures, such as error correction and power control, are also investigated. - Author(s): A. Eriksson ; P. Linnér ; S. Gevorgian
- Source: IEE Proceedings - Microwaves, Antennas and Propagation, Volume 148, Issue 1, p. 51 –55
- DOI: 10.1049/ip-map:20010216
- Type: Article
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Modes in electrically thin circular parallel-plate resonators are discussed in detail. It is shown that the widely used mode indices (found from the field solutions) do not indicate the radial numbers of the field maximums in a straightforward manner. The diameter of the disc, not the radius, accommodates integer numbers of the field maximums (antinodes). These diametrical numbers are expressed in terms of radial mode indices. Emphasis is placed on the first axially symmetric mode TM020, which was incorrectly regarded as TM010 in the past. Some applications of the mode chart, including interpretation of experimental observations, are also discussed. Comparison is made with microstrip and annular resonators. - Author(s): W. Che ; E.K.-N. Yung ; K. Sha ; W. Junding
- Source: IEE Proceedings - Microwaves, Antennas and Propagation, Volume 148, Issue 1, p. 57 –59
- DOI: 10.1049/ip-map:20010219
- Type: Article
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The introduction of a thin dielectric ring helps to increase the differential phase shift of the quadrupole gyromagnetic ferrite variable polariser by about 20~30%. Furthermore, a double-step impedance transformer has been introduced to broaden the bandwidth from 4.06 to 14.5%. The peak power is 750 kW, average power is 500 W, and the switching time is about 25 µs. - Author(s): H.-M. Chen
- Source: IEE Proceedings - Microwaves, Antennas and Propagation, Volume 148, Issue 1, p. 60 –64
- DOI: 10.1049/ip-map:20010224
- Type: Article
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A novel slotted rectangular microstrip antenna for dual-frequency operation is proposed. The microstrip antenna is fed by a single probe feed and has a π-shaped slot embedded close to the patch's radiating edge. The two operating frequencies have the same polarisation planes and similar broadside radiation characteristics. By varying the lengths and the spacing of the two arms of the π-shaped slot, the proposed antenna can have a tunable frequency ratio ranging from about 1.12 to 1.64. Simple semi-empirical formulas of the two operating frequencies have also been obtained. Details of the antenna design and experimental results are presented and discussed. - Author(s): S.-C. Gao ; L.-W. Li ; T.-S. Yeo ; M.-S. Leong
- Source: IEE Proceedings - Microwaves, Antennas and Propagation, Volume 148, Issue 1, p. 65 –71
- DOI: 10.1049/ip-map:20010225
- Type: Article
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The characteristics of a compact, dual-frequency antenna using the slot-loaded meandered rectangular microstrip patch are analysed. The theoretical analysis is based on the finite-difference time-domain (FDTD) method. The FDTD programs are developed and validated by available measurement results. Three different dual-frequency antennas, which include the slot-loaded rectangular patch, the slot-loaded meandered rectangular patch with five slits, and the slot-loaded meandered rectangular patch with 10 slits, are analysed and compared. It is shown that more slits and longer slits could lead to a smaller size of the dual-frequency antenna. The effects of slit lengths on the resonant frequencies and the frequency ratio of the slot-loaded meandered rectangular patch with 10 slits are shown. Several design curves are presented. The electric current distributions on the patch at two resonant frequencies are described, together with the results illustrating the electric field distributions under the patch. The radiation patterns of three dual-frequency antennas are also presented and compared.
Optimised 2D multi-resolution method of moment for printed antenna array modelling
Radiation of a vertical electric dipole over a resistive sheet
Cavity control of active integrated antenna oscillators
Low cost, dual linearly polarised microstrip patch array
Surface wave control using nonperiodic parasitic strips in printed antennas
Propagation in bianisotropic media — reflection and transmission
Broadband suspended plate antenna with probe-fed strip
Wideband U-slot microstrip patch antenna array
Coverage analysis of a stratospheric communication system
Mode chart of electrically thin parallel-plate circular resonators
Quadrupole gyromagnetic ferrite circular variable polariser loaded with a dielectric ring
Single-feed dual-frequency rectangular microstrip antenna with a π-shaped slot
FDTD analysis of a slot-loaded meandered rectangular patch antenna for dual-frequency operation
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