Pub Date : 2004-11-30DOI: 10.1109/HFPSC.2004.1360339
X. Qian, P. Hartmann, A. Wonfor, J. Ingham, R. Penty, I. White
An unfiltered 1310 nm semiconductor optical amplifier is employed as an inline power booster in a low-cost directly-modulated, 100 km radio-over-fibre link to compensate for the attenuation of the fibre. Substantial performance enhancement has been achieved. In addition, an application of this technique within a distributed antenna system with a tree architecture, supporting in excess of 100 antennae, is experimentally simulated.
{"title":"Enhanced performance of a 100km directly-modulated radio-over-fibre link using an unfiltered semiconductor optical amplifier","authors":"X. Qian, P. Hartmann, A. Wonfor, J. Ingham, R. Penty, I. White","doi":"10.1109/HFPSC.2004.1360339","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360339","url":null,"abstract":"An unfiltered 1310 nm semiconductor optical amplifier is employed as an inline power booster in a low-cost directly-modulated, 100 km radio-over-fibre link to compensate for the attenuation of the fibre. Substantial performance enhancement has been achieved. In addition, an application of this technique within a distributed antenna system with a tree architecture, supporting in excess of 100 antennae, is experimentally simulated.","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130114705","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 : 2004-11-30DOI: 10.1109/HFPSC.2004.1360365
S. Ooi, S. Gao, A. Sambell, D. Smith, P. Butterworth
In this paper, a high efficiency, low voltage, class-F power amplifier (PA) is described. The effect of different output harmonic terminations on the power-added efficiency (PAE) of the PA has also been analysed. A medium power PHEMT PA, operating at 900 MHz, is designed and measured. A peak PAE of 71.4% with 22 dBm output power (P/sub out/) and 14 dB power gain (G/sub p/) is achieved at a very low drain voltage (V/sub ds/) of 3 V. A PAE above 60% has been achieved over a bandwidth of 13%.
{"title":"High efficiency class-F power amplifier design","authors":"S. Ooi, S. Gao, A. Sambell, D. Smith, P. Butterworth","doi":"10.1109/HFPSC.2004.1360365","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360365","url":null,"abstract":"In this paper, a high efficiency, low voltage, class-F power amplifier (PA) is described. The effect of different output harmonic terminations on the power-added efficiency (PAE) of the PA has also been analysed. A medium power PHEMT PA, operating at 900 MHz, is designed and measured. A peak PAE of 71.4% with 22 dBm output power (P/sub out/) and 14 dB power gain (G/sub p/) is achieved at a very low drain voltage (V/sub ds/) of 3 V. A PAE above 60% has been achieved over a bandwidth of 13%.","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133045839","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 : 2004-11-30DOI: 10.1109/HFPSC.2004.1360366
E. Dautbegovic, M. Condon, C. Brennan
This paper proposes further improvement to a novel method for the analysis and simulation of ICs recently proposed by the authors. The circuits are assumed to be subjected to input signals that have widely separated rates of variation, e.g. in communication systems an RF carrier modulated by a low-frequency information signal. The previously proposed technique enables the reuse of the results obtained using a lower-order accuracy model to calculate a response of higher-order accuracy model. In this paper, the efficiency of this method is further improved by using a nonlinear model order reduction technique. Results highlight the efficiency of the proposed approach.
{"title":"An efficient wavelet-based nonlinear circuit simulation technique with model order reduction","authors":"E. Dautbegovic, M. Condon, C. Brennan","doi":"10.1109/HFPSC.2004.1360366","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360366","url":null,"abstract":"This paper proposes further improvement to a novel method for the analysis and simulation of ICs recently proposed by the authors. The circuits are assumed to be subjected to input signals that have widely separated rates of variation, e.g. in communication systems an RF carrier modulated by a low-frequency information signal. The previously proposed technique enables the reuse of the results obtained using a lower-order accuracy model to calculate a response of higher-order accuracy model. In this paper, the efficiency of this method is further improved by using a nonlinear model order reduction technique. Results highlight the efficiency of the proposed approach.","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"39 1-2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132124090","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 : 2004-11-30DOI: 10.1109/HFPSC.2004.1360356
F. Mung'au, N. Riley
Summary form only given. The main challenge of this project is concerned with scaling down a radio system such as GPS in terms of positional accuracy and working volumes and mitigation of the potential loss in accuracy due to obstructions. The positioning system proposed is a continuous wave hyperbolic-type system using carrier phase tracking. A hyperbolic positioning system estimates the location of a point by the intersection of hyperboloids which describe the lines of constant difference for the source-receiver range measurements taken from three or more receiver stations. Mitigation of multipath propagation is a major consideration in the successful implementation of such a system and forms the subject for this study.
{"title":"Multipath mitigation in short-range radio based navigation systems","authors":"F. Mung'au, N. Riley","doi":"10.1109/HFPSC.2004.1360356","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360356","url":null,"abstract":"Summary form only given. The main challenge of this project is concerned with scaling down a radio system such as GPS in terms of positional accuracy and working volumes and mitigation of the potential loss in accuracy due to obstructions. The positioning system proposed is a continuous wave hyperbolic-type system using carrier phase tracking. A hyperbolic positioning system estimates the location of a point by the intersection of hyperboloids which describe the lines of constant difference for the source-receiver range measurements taken from three or more receiver stations. Mitigation of multipath propagation is a major consideration in the successful implementation of such a system and forms the subject for this study.","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128094125","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 : 2004-11-30DOI: 10.1109/HFPSC.2004.1360385
L. Krishnamurthy, V. T. Vo, R. Sloan, K. Williams, A. Rezazadeh
This paper describes the design and characterisation of wide band multilayer directional couplers, fabricated on GaAs semi-insulating substrates with two conductive layers of gold separated by polyimide as a dielectric layer, operating at a centre frequency of 24 GHz. These components are very useful in the construction of multilayer MMICs and are compact and easy to design employing multilayer technology. High frequency simulations were carried out using Agilent's Advanced Design System (ADS). In the design iteration, the thickness of the dielectric layer was varied to optimize the coupling and the isolation factors. The effects of metal overlap to improve the isolation factor of the directional couplers have been investigated in full. In this work, on-wafer RF measurements were carried out on the fabricated directional couplers using a HP85107A network analyser. Directional couplers with 90/spl deg/ phase angle, coupling factor of 5 dB and isolation of 10 dB were achieved over the 10 to 35 GHz frequency band. We further compare the results of simulations with those of measured data for final design optimisations.
{"title":"Broadband CPW multilayer directional couplers on GaAs for MMIC applications","authors":"L. Krishnamurthy, V. T. Vo, R. Sloan, K. Williams, A. Rezazadeh","doi":"10.1109/HFPSC.2004.1360385","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360385","url":null,"abstract":"This paper describes the design and characterisation of wide band multilayer directional couplers, fabricated on GaAs semi-insulating substrates with two conductive layers of gold separated by polyimide as a dielectric layer, operating at a centre frequency of 24 GHz. These components are very useful in the construction of multilayer MMICs and are compact and easy to design employing multilayer technology. High frequency simulations were carried out using Agilent's Advanced Design System (ADS). In the design iteration, the thickness of the dielectric layer was varied to optimize the coupling and the isolation factors. The effects of metal overlap to improve the isolation factor of the directional couplers have been investigated in full. In this work, on-wafer RF measurements were carried out on the fabricated directional couplers using a HP85107A network analyser. Directional couplers with 90/spl deg/ phase angle, coupling factor of 5 dB and isolation of 10 dB were achieved over the 10 to 35 GHz frequency band. We further compare the results of simulations with those of measured data for final design optimisations.","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124321020","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 : 2004-11-30DOI: 10.1109/HFPSC.2004.1360346
L. A. Valiente, A. Haigh, A. Gibson
A /spl lambda//4 TEM open-ended coaxial probe cavity operating at 1 GHz is developed to provide profile information for conductor patterns on printed circuit boards. The cavity's inner conductor is terminated in an open circuit probe tip projecting from the resonator's end. The proximity of track metallization reduces the resonance frequency of the sensor and this perturbation is used to extract profile information about the conductor pattern of the sample. A novel 50 /spl Omega/ tapered design is introduced to substantially reduce the cavity's end area, and this in turn reduces the dispersion of the electromagnetic field. This modification significantly improves the resolution of the sensor. The measurement system and the sensor are described and results are presented for two different tapered designs.
{"title":"Scanning microwave coaxial cavity profiler [PCB conductor pattern profiling]","authors":"L. A. Valiente, A. Haigh, A. Gibson","doi":"10.1109/HFPSC.2004.1360346","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360346","url":null,"abstract":"A /spl lambda//4 TEM open-ended coaxial probe cavity operating at 1 GHz is developed to provide profile information for conductor patterns on printed circuit boards. The cavity's inner conductor is terminated in an open circuit probe tip projecting from the resonator's end. The proximity of track metallization reduces the resonance frequency of the sensor and this perturbation is used to extract profile information about the conductor pattern of the sample. A novel 50 /spl Omega/ tapered design is introduced to substantially reduce the cavity's end area, and this in turn reduces the dispersion of the electromagnetic field. This modification significantly improves the resolution of the sensor. The measurement system and the sensor are described and results are presented for two different tapered designs.","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122876710","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 : 2004-11-30DOI: 10.1109/HFPSC.2004.1360386
Yongwei Zhang
A true 3D ray tracing model has been developed for UWB propagation in a typical modern office. A time domain approach is used to determine all dominant paths. The number of rays that have to be considered can then be dramatically reduced for subsequent analyses. The time and spatial properties of the channel are presented. Each dominant path could then be represented by a function with these properties. Predictions of received waveforms were produced by convolving a typical input UWB pulse with these functions. Hence, different input pulse characteristics can be applied and the receiver characteristics rapidly evaluated.
{"title":"Ultra-wide bandwidth channel analysis in time domain using 3-D ray tracing","authors":"Yongwei Zhang","doi":"10.1109/HFPSC.2004.1360386","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360386","url":null,"abstract":"A true 3D ray tracing model has been developed for UWB propagation in a typical modern office. A time domain approach is used to determine all dominant paths. The number of rays that have to be considered can then be dramatically reduced for subsequent analyses. The time and spatial properties of the channel are presented. Each dominant path could then be represented by a function with these properties. Predictions of received waveforms were produced by convolving a typical input UWB pulse with these functions. Hence, different input pulse characteristics can be applied and the receiver characteristics rapidly evaluated.","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125304279","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 : 2004-11-30DOI: 10.1109/HFPSC.2004.1360345
M. Isa, Z. Wu
Microwave radar sensors (MRS) studies are usually based on the analysis of the frequency response of the reflected signal. A MRS system operating at 10.6 GHz, with computer integration, has been built to study the signal characteristic of solid flows. Beans of /spl lambda//4 in size have been used in this study. The amplitude of the reflected signal has been found to be useful in describing the flow characteristics. The amplitude response can be converted into a digital counter with the application of advance signal processing to eliminate noise and unwanted signals. In fact, the system not only counts the number of solids flowing but was also able to identify the size of the solids. Experimental results are presented in this paper.
{"title":"Microwave radar sensor as solid flow counter","authors":"M. Isa, Z. Wu","doi":"10.1109/HFPSC.2004.1360345","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360345","url":null,"abstract":"Microwave radar sensors (MRS) studies are usually based on the analysis of the frequency response of the reflected signal. A MRS system operating at 10.6 GHz, with computer integration, has been built to study the signal characteristic of solid flows. Beans of /spl lambda//4 in size have been used in this study. The amplitude of the reflected signal has been found to be useful in describing the flow characteristics. The amplitude response can be converted into a digital counter with the application of advance signal processing to eliminate noise and unwanted signals. In fact, the system not only counts the number of solids flowing but was also able to identify the size of the solids. Experimental results are presented in this paper.","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129557827","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 : 2004-11-30DOI: 10.1109/HFPSC.2004.1360369
N. Grigoropoulos, S. Tse, P. Young
The purpose of this work is to investigate integrated waveguide structures for low loss millimetre wave components. The guides are based around periodic dielectric structures (non-radiative perforated dielectric waveguides) formed by cylindrical air columns in the material surrounding the dielectric core of an NRD guide. Furthermore, in the centre of the guide, a transition to slotline is introduced to demonstrate one possible technique to integrate 3D waveguides with planar circuitry and microwave monolithic integrated circuits (MMICs).
{"title":"Non-radiative perforated dielectric waveguide (NRPD) with integrated transition to slotline for millimetre-wave components","authors":"N. Grigoropoulos, S. Tse, P. Young","doi":"10.1109/HFPSC.2004.1360369","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360369","url":null,"abstract":"The purpose of this work is to investigate integrated waveguide structures for low loss millimetre wave components. The guides are based around periodic dielectric structures (non-radiative perforated dielectric waveguides) formed by cylindrical air columns in the material surrounding the dielectric core of an NRD guide. Furthermore, in the centre of the guide, a transition to slotline is introduced to demonstrate one possible technique to integrate 3D waveguides with planar circuitry and microwave monolithic integrated circuits (MMICs).","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121799373","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 : 2004-11-30DOI: 10.1109/HFPSC.2004.1360362
D. Treyer, R. Vogt, W. Bachtold
We report on the design of radio frequency (RF) front ends for radio channel sounding applications at 58 GHz. The realized up- and down-converter modules extend the frequency range of an existing real-time channel sounder, which has a maximum RF of 5.8 GHz. To facilitate rapid mm-wave system development, a low-cost 60 GHz prototyping system is introduced. It allows one to test each circuit block in a microstrip test fixture, before connecting it to other circuit blocks using removable electrical and mechanical bonds. The design of V-band microstrip RF filters was challenging because the transverse dimensions of the coupled sections are too wide for utilizing TEM transmission line models and surface-wave effects introduce additional coupling. Electromagnetic optimization was necessary for successful filter design, and this is discussed. The patch antenna and considerations about system dynamic range requirements for multipath measurements are examined.
{"title":"58 GHz front ends for a channel sounder","authors":"D. Treyer, R. Vogt, W. Bachtold","doi":"10.1109/HFPSC.2004.1360362","DOIUrl":"https://doi.org/10.1109/HFPSC.2004.1360362","url":null,"abstract":"We report on the design of radio frequency (RF) front ends for radio channel sounding applications at 58 GHz. The realized up- and down-converter modules extend the frequency range of an existing real-time channel sounder, which has a maximum RF of 5.8 GHz. To facilitate rapid mm-wave system development, a low-cost 60 GHz prototyping system is introduced. It allows one to test each circuit block in a microstrip test fixture, before connecting it to other circuit blocks using removable electrical and mechanical bonds. The design of V-band microstrip RF filters was challenging because the transverse dimensions of the coupled sections are too wide for utilizing TEM transmission line models and surface-wave effects introduce additional coupling. Electromagnetic optimization was necessary for successful filter design, and this is discussed. The patch antenna and considerations about system dynamic range requirements for multipath measurements are examined.","PeriodicalId":405718,"journal":{"name":"High Frequency Postgraduate Student Colloquium, 2004","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126399349","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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