Pub Date : 1983-09-01DOI: 10.1109/EUMA.1983.333281
P. Brand
Today GaAs-FETs are able to generate relative high output power at high frequencies and good efficiency. Therefore they displace GUNN- and IMPATT-diodes in many oscillator and amplifier applications. A big disadvantage of oscillating FETs is their high near carrier noise. But in many cases this problem can be solved by using high Q cavities. In this paper the application of FETs in electronic and mechanical tunable low noise oscillators is shown. A comparison between a feedback and a reverse channel oscillator is made. Measurements of realized circuits are presented. Such oscillators have been developed for use in a digital 13 GHz microwave link system with direct FM service channel.
{"title":"Tunable Low Noise GaAs FET Oscillators at 13 GHZ","authors":"P. Brand","doi":"10.1109/EUMA.1983.333281","DOIUrl":"https://doi.org/10.1109/EUMA.1983.333281","url":null,"abstract":"Today GaAs-FETs are able to generate relative high output power at high frequencies and good efficiency. Therefore they displace GUNN- and IMPATT-diodes in many oscillator and amplifier applications. A big disadvantage of oscillating FETs is their high near carrier noise. But in many cases this problem can be solved by using high Q cavities. In this paper the application of FETs in electronic and mechanical tunable low noise oscillators is shown. A comparison between a feedback and a reverse channel oscillator is made. Measurements of realized circuits are presented. Such oscillators have been developed for use in a digital 13 GHz microwave link system with direct FM service channel.","PeriodicalId":105436,"journal":{"name":"1983 13th European Microwave Conference","volume":"243 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1983-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125204588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-09-01DOI: 10.1109/EUMA.1983.333186
H. Schmiedel, F. Arndt
A computer aided design of a rectangular waveguide H10-H20-mode sensor is demonstrated, which consists of a broad waveguide section with two asymmetric inductive irises, an H-plane asymmetric T-junction and an asymmetric junction to a smaller rectangular guide. The theory is based on field expansion into orthogonal eigenmodes which includes higher-order mode excitation in the computations. Numerical optimization of the design parameters achieves an H10-H20-mode cross-talk attenuation of over 50 dB. Measurements at a simple prototype are in close agreement with theory.
{"title":"Numerical Synthesis of Simple Waveguide Mode Sensors","authors":"H. Schmiedel, F. Arndt","doi":"10.1109/EUMA.1983.333186","DOIUrl":"https://doi.org/10.1109/EUMA.1983.333186","url":null,"abstract":"A computer aided design of a rectangular waveguide H10-H20-mode sensor is demonstrated, which consists of a broad waveguide section with two asymmetric inductive irises, an H-plane asymmetric T-junction and an asymmetric junction to a smaller rectangular guide. The theory is based on field expansion into orthogonal eigenmodes which includes higher-order mode excitation in the computations. Numerical optimization of the design parameters achieves an H10-H20-mode cross-talk attenuation of over 50 dB. Measurements at a simple prototype are in close agreement with theory.","PeriodicalId":105436,"journal":{"name":"1983 13th European Microwave Conference","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1983-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130721238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-09-01DOI: 10.1109/EUMA.1983.333208
N. Linh
Heterojunctions which have been used for years in optoelectronic devices, are now entering in microwave applications. The heterojunction bipolar transistor, proposed since 1957 in not matured in its technology. The new born selectively-doped heterojunction (1978) is gaining in interest in both aspects, physics of the two-dimensional electron-gas (2DEG) and electronic applications. This paper will first recall the transport properties of the 2DEG accumulated at the interface of undoped GaAs-n doped A1GaAs heterunctions. In particular, extremely high mobility and high electron velocity were observed. Growth of these selectively doped heterojunctions by MBE and MOCVD is then described. The best results were obtained by the former technique. Low-noise two-dimensional electron gas FETs (TEGFETs) are presented. With gate length of ~ 0.5¿m noise figure as low as 1.26, 1.4 and 2.3 dB were measured at 10, 12 and 17.5 GHz respectively, with associated gain of 12, 11 and 7.1 dB. The TEGFET have been shown to be the fastest semiconductor device at 300 K with 12.2ps (gate length ~1¿m). They also present low power dissipation (5 times less than conventional GaAs FETs). TEGFET frequency dividers operate up to 5.5 GHz (gate length ~l¿m).
{"title":"GaAs-AlGaAs Epitaxial Growth for Microwave Applications","authors":"N. Linh","doi":"10.1109/EUMA.1983.333208","DOIUrl":"https://doi.org/10.1109/EUMA.1983.333208","url":null,"abstract":"Heterojunctions which have been used for years in optoelectronic devices, are now entering in microwave applications. The heterojunction bipolar transistor, proposed since 1957 in not matured in its technology. The new born selectively-doped heterojunction (1978) is gaining in interest in both aspects, physics of the two-dimensional electron-gas (2DEG) and electronic applications. This paper will first recall the transport properties of the 2DEG accumulated at the interface of undoped GaAs-n doped A1GaAs heterunctions. In particular, extremely high mobility and high electron velocity were observed. Growth of these selectively doped heterojunctions by MBE and MOCVD is then described. The best results were obtained by the former technique. Low-noise two-dimensional electron gas FETs (TEGFETs) are presented. With gate length of ~ 0.5¿m noise figure as low as 1.26, 1.4 and 2.3 dB were measured at 10, 12 and 17.5 GHz respectively, with associated gain of 12, 11 and 7.1 dB. The TEGFET have been shown to be the fastest semiconductor device at 300 K with 12.2ps (gate length ~1¿m). They also present low power dissipation (5 times less than conventional GaAs FETs). TEGFET frequency dividers operate up to 5.5 GHz (gate length ~l¿m).","PeriodicalId":105436,"journal":{"name":"1983 13th European Microwave Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1983-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131006702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-09-01DOI: 10.1109/EUMA.1983.333189
P. Clarricoats, S. Tun, R.C. Brown, C. Parini
The paper describes how mutual coupling influenees both the primary and secondary radiation patterns of array-fed off-set reflector antennas. The principle cause of adverse crosspolarisation is attributed to coupling between the TE11 and TE21 modes in the array. This then is the main cause of crosspolarisation in an optimised dual reflector. It is shown that coupling to the TE21 mode can be minimised with the correct choice of horn.
{"title":"Primary and Secondary Patterns From Array-Fed Off-Set Reflector Antennas","authors":"P. Clarricoats, S. Tun, R.C. Brown, C. Parini","doi":"10.1109/EUMA.1983.333189","DOIUrl":"https://doi.org/10.1109/EUMA.1983.333189","url":null,"abstract":"The paper describes how mutual coupling influenees both the primary and secondary radiation patterns of array-fed off-set reflector antennas. The principle cause of adverse crosspolarisation is attributed to coupling between the TE11 and TE21 modes in the array. This then is the main cause of crosspolarisation in an optimised dual reflector. It is shown that coupling to the TE21 mode can be minimised with the correct choice of horn.","PeriodicalId":105436,"journal":{"name":"1983 13th European Microwave Conference","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1983-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130234888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-09-01DOI: 10.1109/EUMA.1983.333306
J.D. Karlellopoulos, A. Serras
Prediction of the depolarization statistics is studied here using the gamma formulation for the rainrate statistics as well as a special spatial rainrate profile. Numerical results concerning various microwave links sited in U.S.A. are also given.
本文利用伽玛公式和一个特殊的空间雨率剖面研究了去极化统计的预测。并给出了美国各微波链路的数值结果。
{"title":"Prediction of the Rain Depolarization Statistics for a Microwave Radio Link","authors":"J.D. Karlellopoulos, A. Serras","doi":"10.1109/EUMA.1983.333306","DOIUrl":"https://doi.org/10.1109/EUMA.1983.333306","url":null,"abstract":"Prediction of the depolarization statistics is studied here using the gamma formulation for the rainrate statistics as well as a special spatial rainrate profile. Numerical results concerning various microwave links sited in U.S.A. are also given.","PeriodicalId":105436,"journal":{"name":"1983 13th European Microwave Conference","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1983-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126682074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-09-01DOI: 10.1109/EUMA.1983.333270
A. Thompson
This paper outlines a new approach to the design of satellite wind scatterometers which promises a major reduction in power consumption whilst maintaining, or even improving, the measurement accuracy. The approach permits a larger antenna area to be used and allows the available RF energy to be distributed in an efficient manner such that optimum measurement accuracy can be achieved throughout the swath. The proposed scatterometer offers flexibility to accommodate the illumination requirements in the light of more advanced and accurate backscatter coefficient models or the needs of a particular region in the swath. Bias errors caused by satellite attitude uncertainty are reduced. Results are given for a design example in Ku-band.
{"title":"A New Approach to the Design of Wind Scatterometers","authors":"A. Thompson","doi":"10.1109/EUMA.1983.333270","DOIUrl":"https://doi.org/10.1109/EUMA.1983.333270","url":null,"abstract":"This paper outlines a new approach to the design of satellite wind scatterometers which promises a major reduction in power consumption whilst maintaining, or even improving, the measurement accuracy. The approach permits a larger antenna area to be used and allows the available RF energy to be distributed in an efficient manner such that optimum measurement accuracy can be achieved throughout the swath. The proposed scatterometer offers flexibility to accommodate the illumination requirements in the light of more advanced and accurate backscatter coefficient models or the needs of a particular region in the swath. Bias errors caused by satellite attitude uncertainty are reduced. Results are given for a design example in Ku-band.","PeriodicalId":105436,"journal":{"name":"1983 13th European Microwave Conference","volume":"24 7","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1983-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114127124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-09-01DOI: 10.1109/EUMA.1983.333290
E. Kollberg, H. Zirath, M.V. Schneider, A.Y. Chon, A. Jeleński
We present experimental evidence that a single Schottky diode on GaAs is an agglomerate of paralleled microjunctions with different barrier heights and saturation currents. The current-voltage characteristic of the cluster breakes up into sections of exponentials with different slopes as one cools the diode from 300 K to 10 K. Noise measurements performed on cooled diodes at 4 GHz also confirm that a single device is a cluster of paralleled diodes. The model suggests a more compl icated equivalent cicuit of the diode which can also explain some of the problems experienced in attempts to theoretically predict cooled mixer noise performance. It also explains why in some diodes the excess noise appears at lower currents levels than in other diodes, a phenomenon which seriously degrades the low noise preformance of the mixer.
{"title":"Characteristics of Millimeter-Wave Schottky Diodes with Microcluster Interface","authors":"E. Kollberg, H. Zirath, M.V. Schneider, A.Y. Chon, A. Jeleński","doi":"10.1109/EUMA.1983.333290","DOIUrl":"https://doi.org/10.1109/EUMA.1983.333290","url":null,"abstract":"We present experimental evidence that a single Schottky diode on GaAs is an agglomerate of paralleled microjunctions with different barrier heights and saturation currents. The current-voltage characteristic of the cluster breakes up into sections of exponentials with different slopes as one cools the diode from 300 K to 10 K. Noise measurements performed on cooled diodes at 4 GHz also confirm that a single device is a cluster of paralleled diodes. The model suggests a more compl icated equivalent cicuit of the diode which can also explain some of the problems experienced in attempts to theoretically predict cooled mixer noise performance. It also explains why in some diodes the excess noise appears at lower currents levels than in other diodes, a phenomenon which seriously degrades the low noise preformance of the mixer.","PeriodicalId":105436,"journal":{"name":"1983 13th European Microwave Conference","volume":"14 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1983-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114007471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-09-01DOI: 10.1109/EUMA.1983.333202
J. Bolomey, D. Picard
This paper is devoted to the discussion of available measurement accuracies of linear arrays operating according to the modulated scattering technique. The combination of a fast electronic scanning on a line with a rotation of the antenna under test provides a substantial reduction of the near field probing duration as compared to fully mechanical scanning solutions. The effects of coupling, fabrication tolerances and components dispersion have been numerically simulated.
{"title":"Error Analysis in Fast Near Field Probing by the Modulated Scattering Technique","authors":"J. Bolomey, D. Picard","doi":"10.1109/EUMA.1983.333202","DOIUrl":"https://doi.org/10.1109/EUMA.1983.333202","url":null,"abstract":"This paper is devoted to the discussion of available measurement accuracies of linear arrays operating according to the modulated scattering technique. The combination of a fast electronic scanning on a line with a rotation of the antenna under test provides a substantial reduction of the near field probing duration as compared to fully mechanical scanning solutions. The effects of coupling, fabrication tolerances and components dispersion have been numerically simulated.","PeriodicalId":105436,"journal":{"name":"1983 13th European Microwave Conference","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1983-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123036726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-09-01DOI: 10.1109/EUMA.1983.333272
G. Ediss, G. Schneider, N. Keen, J. Baars
This paper reports a two channel, coherent holography receiver for the measurement of the two dimensional reflector profile of the 30 m millimeter radio telescope at Pico Veleta, Spain. Using a phase and frequency locked Gunn oscillator as local oscillator, a path length difference of 30 ¿m can be measured.
{"title":"A Two Channel Receiver at 22 GHz for Holographic Measurement of Reflector Antenna Profiles","authors":"G. Ediss, G. Schneider, N. Keen, J. Baars","doi":"10.1109/EUMA.1983.333272","DOIUrl":"https://doi.org/10.1109/EUMA.1983.333272","url":null,"abstract":"This paper reports a two channel, coherent holography receiver for the measurement of the two dimensional reflector profile of the 30 m millimeter radio telescope at Pico Veleta, Spain. Using a phase and frequency locked Gunn oscillator as local oscillator, a path length difference of 30 ¿m can be measured.","PeriodicalId":105436,"journal":{"name":"1983 13th European Microwave Conference","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1983-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122435186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-09-01DOI: 10.1109/EUMA.1983.333224
W. Menzel
First results of a 140 GHz finline balanced mixer are reported. The mixer is based on the cambination of finline and coplanar line. Schottky-barrier beam-lead diodes are used as mixer diodes. This mixer, together with other finline components under developnent, gives the basis for low-cost 140 GHz integrated finline circuits.
{"title":"A 140 GHz Balanced Mixer for Finline Integrated Circuits","authors":"W. Menzel","doi":"10.1109/EUMA.1983.333224","DOIUrl":"https://doi.org/10.1109/EUMA.1983.333224","url":null,"abstract":"First results of a 140 GHz finline balanced mixer are reported. The mixer is based on the cambination of finline and coplanar line. Schottky-barrier beam-lead diodes are used as mixer diodes. This mixer, together with other finline components under developnent, gives the basis for low-cost 140 GHz integrated finline circuits.","PeriodicalId":105436,"journal":{"name":"1983 13th European Microwave Conference","volume":"104 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1983-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122629565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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