Online ISSN
1350-911X
Print ISSN
0013-5194
Electronics Letters
Volume 7, Issue 9, 6 May 1971
Volumes & issues:
-
Volume 59 (2023)
-
Volume 58 (2022)
-
Volume 57 (2021)
-
Volume 56 (2020)
-
Volume 55 (2019)
-
Volume 54 (2018)
-
Volume 53 (2017)
-
Volume 52 (2016)
-
Volume 51 (2015)
-
Volume 50 (2014)
-
Volume 49 (2013)
-
Volume 48 (2012)
-
Volume 47 (2011)
-
Volume 46 (2010)
-
Volume 45 (2009)
-
Volume 44 (2008)
-
Volume 43 (2007)
-
Volume 42 (2006)
-
Volume 41 (2005)
-
Volume 40 (2004)
-
Volume 39 (2003)
-
Volume 38 (2002)
-
Volume 37 (2001)
-
Volume 36 (2000)
-
Volume 35 (1999)
-
Volume 34 (1998)
-
Volume 33 (1997)
-
Volume 32 (1996)
-
Volume 31 (1995)
-
Volume 30 (1994)
-
Volume 29 (1993)
-
Volume 28 (1992)
-
Volume 27 (1991)
-
Volume 26 (1990)
-
Volume 25 (1989)
-
Volume 24 (1988)
-
Volume 23 (1987)
-
Volume 22 (1986)
-
Volume 21 (1985)
-
Volume 20 (1984)
-
Volume 19 (1983)
-
Volume 18 (1982)
-
Volume 17 (1981)
-
Volume 16 (1980)
-
Volume 15 (1979)
-
Volume 14 (1978)
-
Volume 13 (1977)
-
Volume 12 (1976)
-
Volume 11 (1975)
-
Volume 10 (1974)
-
Volume 9 (1973)
-
Volume 8 (1972)
-
Volume 7 (1971)
-
Volume 6 (1970)
-
Volume 5 (1969)
-
Volume 4 (1968)
-
Volume 3 (1967)
-
Volume 2 (1966)
-
Volume 1 (1965)
Volume 7, Issue 9
6 May 1971
Compensator to maintain observability while decoupling
- Author(s): M. Cremer
- Source: Electronics Letters, Volume 7, Issue 9, p. 201 –203
- DOI: 10.1049/el:19710136
- Type: Article
- + Show details - Hide details
-
p.
201
–203
(3)
In many linear multivariable systems, the loss of complete observability is the price of decoupling by state feedback. A design procedure is presented for a compensator by which either all modes or only the unstable modes of the system are made observable; these would be unobservable without the compensator. This additional dynamic system is not a compensator in the common sense, since it is driven by the state of the plant and does not serve as a state estimator.
Vibration-mode patterns of acoustoelectric oscillators
- Author(s): F.G. Marshall
- Source: Electronics Letters, Volume 7, Issue 9, p. 203 –205
- DOI: 10.1049/el:19710137
- Type: Article
- + Show details - Hide details
-
p.
203
–205
(3)
The major plate resonances of acoustoelectric oscillators have often been observed to be split into a number of components separated by a few tens of kilohertz. An apparatus has been developed which displays the vibration mode pattern for each component of a spectrum of closely separated lines. The patterns observed may be understood if the principal components of the split line are members of the inharmonic series of vibrations allowed for the particular oscillator geometry used.
Multiplication of complex numbers using iterative arrays
- Author(s): J. Deverell
- Source: Electronics Letters, Volume 7, Issue 9, p. 205 –207
- DOI: 10.1049/el:19710138
- Type: Article
- + Show details - Hide details
-
p.
205
–207
(3)
A digital multiplier which can handle complex numbers in any quadrant is described. The multiplier is based on two cellular logic arrays which are fully iterative and which are thus suitable for large-scale integration. Each cell in each of the arrays is based on two conventional multiplier cells.
Synthesis of linear multivariable feedback systems with prescribed stochastic-response characteristics
- Author(s): B. Porter
- Source: Electronics Letters, Volume 7, Issue 9, p. 207 –208
- DOI: 10.1049/el:19710139
- Type: Article
- + Show details - Hide details
-
p.
207
–208
(2)
The letter presents a simple method of synthetising a class of linear multivariable feedback systems with prescribed steady-state stochastic-response characteristics.
Prescribed stability optimal controller for time-delay systems
- Author(s): D.H. Eller and R.P. Rhoten
- Source: Electronics Letters, Volume 7, Issue 9, p. 208 –209
- DOI: 10.1049/el:19710140
- Type: Article
- + Show details - Hide details
-
p.
208
–209
(2)
The letter considers optimal-controller design for systems described by constant-coefficient linear-differential-difference equations. The performance-measure integrand is a time-weighted quadratic form in the state and control, and by virtue of a variable substitution, existing solutions for the non-time-weighted-integrand case may be applied.
Negative resistance from velocity-saturated nonuniform semiconductor samples
- Author(s): I. LundströM and R.L. Wierich
- Source: Electronics Letters, Volume 7, Issue 9, p. 209 –211
- DOI: 10.1049/el:19710141
- Type: Article
- + Show details - Hide details
-
p.
209
–211
(3)
It is shown that a negative small-signal resistance may occur in a nonuniform semiconductor sample with ohmic contacts under a d.c. bias giving drift-velocity saturation. A circular sample is considered for convenience.
Generalisation of a theorem by mitra and hurtig on positive real functions
- Author(s): S. Tirtoprodjo
- Source: Electronics Letters, Volume 7, Issue 9, p. 211 –212
- DOI: 10.1049/el:19710142
- Type: Article
- + Show details - Hide details
-
p.
211
–212
(2)
Utilising a polar-plot approach, a theorem by Mitra and Hurtig on positive real (p.r.) functions with noninterlaced real distinct poles and zeros is shown to be a special case of a generalised theorem on p.r. functions with noninterlaced real multiple poles and zeros.
Improved algorithm for road-traffic control
- Author(s): N. Gartner
- Source: Electronics Letters, Volume 7, Issue 9, p. 212 –214
- DOI: 10.1049/el:19710143
- Type: Article
- + Show details - Hide details
-
p.
212
–214
(3)
An algorithm for the systematic co-ordination of traffic signals in urban areas is described. The delay time for traffic is minimised by selecting a series-parallel pattern of the road network. A practical procedure is proposed for determining the optimum pattern.
Wave impedance from atmospheric noise near 2 kHz
- Author(s): D.B. Large
- Source: Electronics Letters, Volume 7, Issue 9, p. 214 –215
- DOI: 10.1049/el:19710144
- Type: Article
- + Show details - Hide details
-
p.
214
–215
(2)
Atmospheric radio-noise measurements near the upper end of the e.l.f. band often indicate absorption and interference effects which are not present over most of the e.l.f. and v.l.f. bands. One such phenomenon is the sharp peaking of the magnitude of the ratio of vertical E to horizontal H, i.e. of the wave impedance characterising propagation in the earth-ionosphere waveguide. This paper gives a brief qualitative description of this phenomenon, and shows that its basic features may be attributed to interference between two waveguide modes. In addition, the possibility of using swept-frequency impedance measurements to precisely locate isolated thunderstorms is discussed.
Lightning and the long spark
- Author(s): T.E. Allibone
- Source: Electronics Letters, Volume 7, Issue 9, p. 215 –216
- DOI: 10.1049/el:19710145
- Type: Article
- + Show details - Hide details
-
p.
215
–216
(2)
The attractive power of an earthed pointed conductor, rising a short distance out of an earthed plane, for a descending leader stroke to a lightning flash or to a high-voltage impulse discharge has been well established; the laboratory discharge is strongly attracted to such a pointed conductor when the high-voltage electrode is of negative polarity, but not so strongly for a positive-polarity electrode for the same gap spacing. Previous work was done with a fast-front impulse wave. The same results have now been obtained using impulses having wavefronts of 12 and of 160 μs duration, wavefronts more closely resembling lightning-current wavefronts.
Sweep-frequency measurement of structural return loss by a carrier-burst method
- Author(s): G. Rosman
- Source: Electronics Letters, Volume 7, Issue 9, p. 216 –217
- DOI: 10.1049/el:19710146
- Type: Article
- + Show details - Hide details
-
p.
216
–217
(2)
Errors due to hybrid unbalance and reflections from connectors and terminations are eliminated by using a burst of carrier as the test signal. A sampling oscilloscope extracts that part of the signal which is proportional to the reflection from the cable alone.
Interdigital piezoelectric Rayleighwave transducer: an improved equivalent circuit
- Author(s): R.F. Milsom and M. Redwood
- Source: Electronics Letters, Volume 7, Issue 9, p. 217 –218
- DOI: 10.1049/el:19710147
- Type: Article
- + Show details - Hide details
-
p.
217
–218
(2)
A more accurate representation of an interdigital array is obtained by using an equivalent circuit intermediate between the crossed-field and in-line-field models, with negative capacitance, velocity, length and coupling dependent on the electrode-width/gap-between-electrodes ratio.
Fast algorithm for digital logarithmic conversion
- Author(s): G.A. Jullien
- Source: Electronics Letters, Volume 7, Issue 9, p. 218 –220
- DOI: 10.1049/el:19710148
- Type: Article
- + Show details - Hide details
-
p.
218
–220
(3)
The use of homomorphic filtering in many problems involving nonlinear combination of signals requires complex logarithmic converters. A fast algorithm for digital logarithmic conversion is developed which uses simple computer manipulations. The algorithm trades accuracy for speed, but is found to be adequate in a number of applications tested so far.
Coplanar-guide and slot-guide junction circulators
- Author(s): N. Ogasawara and M. Kaji
- Source: Electronics Letters, Volume 7, Issue 9, p. 220 –221
- DOI: 10.1049/el:19710149
- Type: Article
- + Show details - Hide details
-
p.
220
–221
(2)
A variety of Y circulators derived from the coplanar or slot guide, whose feasibilities are verified experimentally, are presented. The indication is added that the field-confinement scheme may profitably be resorted to.
Doping-dependent mobility analysis of junction field-effect transistors
- Author(s): K.V. Ramanan and R.K. Gupta
- Source: Electronics Letters, Volume 7, Issue 9, p. 221 –224
- DOI: 10.1049/el:19710150
- Type: Article
- + Show details - Hide details
-
p.
221
–224
(4)
An analysis of a junction field-effect transistor, taking into account the doping-dependent mobility, is presented for an assumed arbitrary impurity distribution in the channel. The values of transconductance and drain current obtained from the new relationships are found to deviate considerably from the theoretical values of these parameters estimated from the existing relationships.
Stability of a wideband gyrator circuit
- Author(s): J.G. Wade and D.W. Parker
- Source: Electronics Letters, Volume 7, Issue 9, p. 224 –225
- DOI: 10.1049/el:19710151
- Type: Article
- + Show details - Hide details
-
p.
224
–225
(2)
The stability of a practical wideband gyrator circuit is discussed. Its tendency to be stable is attributed to automatic neutralisation of the feedback capacity associated with the practical transconductance amplifiers. It is also shown that this built-in stabilisation is absent from a typical gyrator circuit incorporating emitter followers with the transconductance amplifiers.
Fast versatile binary comparator array
- Author(s): H.H. Guild
- Source: Electronics Letters, Volume 7, Issue 9, p. 225 –226
- DOI: 10.1049/el:19710152
- Type: Article
- + Show details - Hide details
-
p.
225
–226
(2)
A 1-dimensional cascaded structure is normally employed with binary comparators operating in the parallel mode. An assignment of cell output states is proposed which enables a faster 2-dimensional array to be formed. An optional facility for detecting inputs of zero value may be simply incorporated in the design.
Two-dimensional analysis of lateral-base transistors
- Author(s): J.A. Kilpatrick and W.D. Ryan
- Source: Electronics Letters, Volume 7, Issue 9, p. 226 –227
- DOI: 10.1049/el:19710153
- Type: Article
- + Show details - Hide details
-
p.
226
–227
(2)
Numerical methods are used to show that when p-n-p lateral-base transistors are analysed, the emitter efficiency must be considered. A comparison is made between two such transistors, one with a buried n layer, and the other without.
Elimination of nonlinear effects in impulse-response testing
- Author(s): G.C. Moss and K.C. Ng
- Source: Electronics Letters, Volume 7, Issue 9, p. 227 –229
- DOI: 10.1049/el:19710154
- Type: Article
- + Show details - Hide details
-
p.
227
–229
(3)
All methods to date proposed for removing the effect of output nonlinearities on impulse-response estimates either use multilevel input test signals or are based on two or more tests with input signals of different amplitudes. A method is proposed for systems constrained to respond to two levels only, and is applied to a simulated system.
Logarithmic convertor
- Author(s): J.D. Nicoud and R. Dessoulavy
- Source: Electronics Letters, Volume 7, Issue 9, p. 230 –231
- DOI: 10.1049/el:19710155
- Type: Article
- + Show details - Hide details
-
p.
230
–231
(2)
A specialised system for computing logarithms and anti-logarithms in binary form is described. A great simplicity is obtained if the base is of the form 1+2−k. The precision is discussed and two examples are given. The computing time is, with t.t.l. circuits, of the order of 1 ms in the usual range of the analogue logarithmic convertors, and does not increase very much when the range of the numbers and the precision increase.
Silicon p-n junction photodiode characteristics with variable drift field in the diffused region
- Author(s): A.B. Bhattacharyya ; A.K. Tagore ; T.N. Basavaraj
- Source: Electronics Letters, Volume 7, Issue 9, p. 231 –233
- DOI: 10.1049/el:19710156
- Type: Article
- + Show details - Hide details
-
p.
231
–233
(3)
The continuity equation for the minority carriers, considering the actual field variation in the diffused region of a photodiode with a complementary-error-function impurity distribution, has been solved in terms of a power series. The essential parameters, such as excess minority-carrier profile, short-circuit current, surface loss and collection efficiency have been calculated.
Amplification of acoustic surface waves by means of a broadband hybrid-junction transducer and negative-resistance circuits
- Author(s): R. Krimholtz and G.L. Matthaei
- Source: Electronics Letters, Volume 7, Issue 9, p. 233 –235
- DOI: 10.1049/el:19710157
- Type: Article
- + Show details - Hide details
-
p.
233
–235
(3)
The letter describes an interdigital surface-wave transducer with properties closely analogous to those of an electromagnetic quadrature hybrid junction. If the two electrical ports of such a hybrid-junction transducer are terminated in appropriate negative resistances, transmission gain is observed for an incident acoustic surface wave.
Computation of equivalent wave source using the adjoint network
- Author(s): J.W. Bandler and R.E. Seviora
- Source: Electronics Letters, Volume 7, Issue 9, p. 235 –236
- DOI: 10.1049/el:19710158
- Type: Article
- + Show details - Hide details
-
p.
235
–236
(2)
A method for computing the equivalent wave source at some port of an excited reciprocal or nonreciprocal network using one analysis of the appropriately terminated adjoint network is presented. The procedure should be useful in simplifying the scattering-matrix analysis of complicated networks.
Erratum: Pulse response of 0°Z cut ADP modulators
- Author(s): K. Rashidi
- Source: Electronics Letters, Volume 7, Issue 9, page: 236 –236
- DOI: 10.1049/el:19710159
- Type: Article
- + Show details - Hide details
-
p.
236
(1)
Most viewed content for this Journal
Article
content/journals/el
Journal
5
Most cited content for this Journal
-
Extreme multistability in a memristive circuit
- Author(s): Bo-Cheng Bao ; Quan Xu ; Han Bao ; Mo Chen
- Type: Article
-
Absorptive frequency selective surface using parallel LC resonance
- Author(s): Qiang Chen ; Liguo Liu ; Liang Chen ; Jiajun Bai ; Yunqi Fu
- Type: Article
-
Partial spectral search-based DOA estimation method for co-prime linear arrays
- Author(s): Fenggang Sun ; Peng Lan ; Bin Gao
- Type: Article
-
Experimental verification of on-chip CMOS fractional-order capacitor emulators
- Author(s): G. Tsirimokou ; C. Psychalinos ; A.S. Elwakil ; K.N. Salama
- Type: Article
-
54 Gbit/s OOK transmission using single-mode VCSEL up to 2.2 km MMF
- Author(s): G. Stepniak ; A. Lewandowski ; J.R. Kropp ; N.N. Ledentsov ; V.A. Shchukin ; N. Ledentsov Jr. ; G. Schaefer ; M. Agustin ; J.P. Turkiewicz
- Type: Article
