110 research outputs found

    A coupled-line balun for ultra-wideband single-balanced diode mixer

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    A multi-section coupled-line balun design for an ultra-wideband diode mixer is presented in this paper. The multi-section coupled-line balun was used to interface with the diode mixer in which it can deliver a good impedance matching between the diode mixer and input/output ports. The mixer design operates with a Local Oscillator (LO) power level of 10 dBm, Radio Frequency (RF) power level of -20 dBm and Intermediate Frequency (IF) of 100 MHz with the balun characteristic of 180° phase shift over UWB frequency (3.1 to 10.6 GHz), the mixer design demonstrated a good conversion loss of -8 to -16 dB over the frequency range from 3.1 to 10.6 GHz. Therefore, the proposed multi-section coupled-line balun for application of UWB mixer showed a good isolation between the mixer’s ports

    Review Of Mixer And Balun Designs For Uwb Applications

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    This paper presents an important review on mixer and balun designs for several UWB (ultra-wideband) applications that generally operate in frequencies ranging from 3.1 to 10.6 GHz. This paper begins with an introduction of mixer and balun terminologies, followed by discussion and comparison of several types of mixer designs and their performance on conversion gain, noise figure, third-order intercept points input, and port-to-port isolation. Balun plays an important role in RF mixer designs as it converts the single-ended signal coming from LNA into a differential signal that suitable for mixer input terminal. Hence, baluns provide impedance transformation and matching network for structures transition in mixer designs. The previous studies are reviewed and compared in order to gain a better understanding in RF mixers. An alternative design of balun can be suggested to be utilized in mixer designs to produce overall good performance for multi- function operation in UWB applications

    A Coupled-Line Balun For Ultra-Wideband Single-Balanced Diode Mixer

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    A multi-section coupled-line balun design for an ultra-wideband diode mixer is presented in this paper. The multi-section coupled-line balun was used to interface with the diode mixer in which it can deliver a good impedance matching between the diode mixer and input/output ports. The mixer design operates with a Local Oscillator (LO) power level of 10 dBm, Radio Frequency (RF) power level of -20 dBm and Intermediate Frequency (IF) of 100 MHz with the balun characteristic of 180° phase shift over UWB frequency (3.1 to 10.6 GHz), the mixer design demonstrated a good conversion loss of -8 to -16 dB over the frequency range from 3.1 to 10.6 GHz. Therefore, the proposed multi-section coupled-line balun for application of UWB mixer showed a good isolation between the mixer’s port

    Hardware Development of an Ultra-Wideband System for High Precision Localization Applications

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    A precise localization system in an indoor environment has been developed. The developed system is based on transmitting and receiving picosecond pulses and carrying out a complete narrow-pulse, signal detection and processing scheme in the time domain. The challenges in developing such a system include: generating ultra wideband (UWB) pulses, pulse dispersion due to antennas, modeling of complex propagation channels with severe multipath effects, need for extremely high sampling rates for digital processing, synchronization between the tag and receivers’ clocks, clock jitter, local oscillator (LO) phase noise, frequency offset between tag and receivers’ LOs, and antenna phase center variation. For such a high precision system with mm or even sub-mm accuracy, all these effects should be accounted for and minimized. In this work, we have successfully addressed many of the above challenges and developed a stand-alone system for positioning both static and dynamic targets with approximately 2 mm and 6 mm of 3-D accuracy, respectively. The results have exceeded the state of the art for any commercially available UWB positioning system and are considered a great milestone in developing such technology. My contributions include the development of a picosecond pulse generator, an extremely wideband omni-directional antenna, a highly directive UWB receiving antenna with low phase center variation, an extremely high data rate sampler, and establishment of a non-synchronized UWB system architecture. The developed low cost sampler, for example, can be easily utilized to sample narrow pulses with up to 1000 GS/s while the developed antennas can cover over 6 GHz bandwidth with minimal pulse distortion. The stand-alone prototype system is based on tracking a target using 4-6 base stations and utilizing a triangulation scheme to find its location in space. Advanced signal processing algorithms based on first peak and leading edge detection have been developed and extensively evaluated to achieve high accuracy 3-D localization. 1D, 2D and 3D experiments have been carried out and validated using an optical reference system which provides better than 0.3 mm 3-D accuracy. Such a high accuracy wireless localization system should have a great impact on the operating room of the future

    A 77-GHz Phased-Array Transceiver With On-Chip Antennas in Silicon: Receiver and Antennas

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    In this paper, we present the receiver and the on-chip antenna sections of a fully integrated 77-GHz four-element phased-array transceiver with on-chip antennas in silicon. The receiver section of the chip includes the complete down-conversion path comprising low-noise amplifier (LNA), frequency synthesizer, phase rotators, combining amplifiers, and on-chip dipole antennas. The signal combining is performed using a novel distributed active combining amplifier at an IF of 26 GHz. In the LO path, the output of the 52-GHz VCO is routed to different elements and can be phase shifted locally by the phase rotators. A silicon lens on the backside is used to reduce the loss due to the surface-wave power of the silicon substrate. Our measurements show a single-element LNA gain of 23 dB and a noise figure of 6.0 dB. Each of the four receive paths has a gain of 37 dB and a noise figure of 8.0 dB. Each on-chip antenna has a gain of +2 dBi

    Passive and active circuits in cmos technology for rf, microwave and millimeter wave applications

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    The permeation of CMOS technology to radio frequencies and beyond has fuelled an urgent need for a diverse array of passive and active circuits that address the challenges of rapidly emerging wireless applications. While traditional analog based design approaches satisfy some applications, the stringent requirements of newly emerging applications cannot necessarily be addressed by existing design ideas and compel designers to pursue alternatives. One such alternative, an amalgamation of microwave and analog design techniques, is pursued in this work. A number of passive and active circuits have been designed using a combination of microwave and analog design techniques. For passives, the most crucial challenge to their CMOS implementation is identified as their large dimensions that are not compatible with CMOS technology. To address this issue, several design techniques – including multi-layered design and slow wave structures – are proposed and demonstrated through experimental results after being suitably tailored for CMOS technology. A number of novel passive structures - including a compact 10 GHz hairpin resonator, a broadband, low loss 25-35 GHz Lange coupler, a 25-35 GHz thin film microstrip (TFMS) ring hybrid, an array of 0.8 nH and 0.4 nH multi-layered high self resonant frequency (SRF) inductors are proposed, designed and experimentally verified. A number of active circuits are also designed and notable experimental results are presented. These include 3-10 GHz and DC-20 GHz distributed low noise amplifiers (LNA), a dual wideband Low noise amplifier and 15 GHz distributed voltage controlled oscillators (DVCO). Distributed amplifiers are identified as particularly effective in the development of wideband receiver front end sub-systems due to their gain flatness, excellent matching and high linearity. The most important challenge to the implementation of distributed amplifiers in CMOS RFICs is identified as the issue of their miniaturization. This problem is solved by using integrated multi-layered inductors instead of transmission lines to achieve over 90% size compression compared to earlier CMOS implementations. Finally, a dual wideband receiver front end sub-system is designed employing the miniaturized distributed amplifier with resonant loads and integrated with a double balanced Gilbert cell mixer to perform dual band operation. The receiver front end measured results show 15 dB conversion gain, and a 1-dB compression point of -4.1 dBm in the centre of band 1 (from 3.1 to 5.0 GHz) and -5.2 dBm in the centre of band 2 (from 5.8 to 8 GHz) with input return loss less than 10 dB throughout the two bands of operation

    SiGe-based broadband and high suppression frequency doubler ICs for wireless communications

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    制度:新 ; 報告番号:甲3419号 ; 学位の種類:博士(工学) ; 授与年月日:2011/9/15 ; 早大学位記番号:新574

    GigaHertz Symposium 2010

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    Millimeter-Wave Concurrent Dual-Band BiCMOS RFIC Transmitter for Radar and Communication Systems

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    This dissertation presents new circuit architectures and techniques for improving the performance of several key BiCMOS RFIC building blocks used in radar and wireless communication systems operating up to millimeter-wave frequencies, and the development of an advanced, low-cost and miniature millimeter-wave concurrent dual-band transmitter for short-range, high-resolution radar and high-rate communication systems. A new type of low-power active balun consisting of a common emitter amplifier with degenerative inductor and a common collector amplifier is proposed. The parasitic neutralization and compensation techniques are used to keep the balun well balanced at very high frequencies and across an ultra-wide bandwidth. A novel RF switch architecture with ultra-high isolation and possible gain is proposed, analyzed and demonstrated. The new RF switch architecture achieves an ultra-high isolation through implementation of a new RF leaking cancellation technique. A new class of concurrent dual-band impedance matching networks and technique for synthesizing them are presented together with a 25.5/37-GHz concurrent dual-band PA. These matching networks enable simultaneous matching of two arbitrary loads to two arbitrary sources at two different frequencies, utilizing the impedance-equivalence properties of LC networks that any LC network can be equivalent to an inductor, capacitor, open or short at different frequencies. K- and Ka-band ultra-low-leakage RF-pulse formers capable of producing very narrow RF pulses in the order of 200 ps with small rising and falling time for short-range high-resolution radar and high-data-rate communication systems are also developed. The complete transmitter exhibiting unique characteristics obtained from capabilities of producing very narrow and tunable RF pulses with extremely RF leakage and working concurrently in dual bands at 24.5 and 35 GHz was designed. Capability of generating narrow and tunable RF pulses allows the radar system to flexibly work at high and multiple range resolutions. The extremely low RF leakage allows the transmitter to share one antenna system with receiver, turn on the PA at all time, comply the transmitting spectrum requirements, increase the system dynamic range, avoid harming to other systems; hence improving system size, cost and performance. High data-rate in communication systems is achieved as the consequence of transmitting very narrow RF pulses at high rates. In addition, the dissertation demonstrates a design approach for low chip-area, cost and power consumption systems in which a single dual-band component (power amplifier) is designed to operate with two RF signals simultaneously
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