Emilia Moldovan

A new direct millimeter wave six-port receiver

A new direct conversion wide band (23 GHz-31 GHz) six-port millimeter wave receiver suitable for integrated circuit fabrication is proposed to satisfy mass-market wireless communications. The receiver contains one multi chip module (MCM) consisting of a wide band six-port junction, four RF detectors (Schottky diodes), video amplifiers and I&Q decoder. The prototype circuits are fabricated in hybrid integrated circuits, and the receiver topology is suitable for fabrication in microwave monolithic integrated circuits (MMICs). This new hardware receiver is proposed as a robust, rugged, low cost receiver for use in wide band wireless mass market QPSK communications. Hand held and laptop terminals for future e-mail/multimedia services are a prime example of communication equipment needing such receivers. BER measurements and simulation results are presented in the presence of noise, adjacent signal interference, local oscillator (LO) phase shift and LO phase noise.

A new direct millimeter-wave six-port receiver

A new direct conversion wide band (23 GHz-31 GHz) six-port millimeter wave receiver suitable for integrated circuit fabrication is proposed to satisfy mass-market wireless communications. The receiver contains one multi chip module (MCM) consisting of a wide band six-port junction, four RF detectors (Schottky diodes), video amplifiers and I&Q decoder. The prototype circuits are fabricated in hybrid integrated circuits, and the receiver topology is suitable for fabrication in microwave monolithic integrated circuits (MMICs). This new hardware receiver is proposed as a robust, rugged, low cost receiver for use in wide band wireless mass market QPSK communications. Hand held and laptop terminals for future e-mail/multimedia services are a prime example of communication equipment needing such receivers. BER measurements and simulation results are presented in the presence of noise, adjacent signal interference, local oscillator (LO) phase shift and LO phase noise.

W-band multiport substrate-integrated waveguide circuits

Millimeter-wave passive circuits that are designed and fabricated in the form of substrate-integrated waveguide (SIW) are presented in this paper. A W-band SIW 90/spl deg/ hybrid coupler and multiport SIW circuit are made and synthesized on alumina substrate using metallized slot arrays. In order to connect the SIW circuits with WR-10 standard rectangular waveguides for measurement purposes, a new transition is also proposed and developed. Such millimeter-wave integrated passive circuits are developed for applications in radar sensors operating at 94 GHz. Performances of these circuits are evaluated and discussed on the basis of a series of S-parameter simulations and measurements. Excellent agreement between simulated and measured results is observed.

Ka-band analog front-end for software-defined direct conversion receiver

A six-port Ka-band front-end architecture based on direct conversion for a software-defined radio application is proposed in this paper. The direct conversion is accomplished using six-port technology. In order to demodulate various phase-shift-keying/quadrature-amplitude-modulation (PSK/QAM) modulated signals at a high bit rate, a new analog baseband circuit was specially designed according to the I/Q equations presented in the theoretical part. An experimental prototype has been fabricated and measured. Simulation and measurement results for binary PSK, quaternary PSK (QPSK), 8 PSK, 16 PSK, and 16 QAM modulated signals at a bit rate up to 40 Mb/s are presented to validate the proposed approach. A software-defined radio can be designed using the new front-end and only two analog-to-digital converters (ADCs) because the I/Q output signals are generated by analog means. Previous six-port receivers make use of four ADCs to read the six-port dc levels and require digital computations to generate the I/Q output signals. With the proposed approach, the load of the signal processor will therefore be reduced and the modulation speed can be significantly increased using the same digital signal processor.

A new 94-GHz six-port collision-avoidance radar sensor

A new 94-GHz collision avoidance radar sensor is proposed. The receiver front-end module is based on a six-port phase/frequency discriminator (SPD). The SPD, composed of four 90/spl deg/ hybrid couplers, is manufactured in a metal block of brass using a computer numerically controlled milling machine. Simulation and measurement S-parameters of the SPD are presented in the frequency band. New SPD computer models are generated and used in the system simulations. Preliminary measurements and system simulations performed to obtain the relative velocity of the target and its distance are presented. Statistical evaluations show an acceptable measurement error of this radar sensor.

Ka-band direct digital receiver

A new direct-conversion wideband (26-28.5 GHz) six-port receiver is proposed for mass-market wireless communications. This six-port receiver is designed to operate without the need for precise power reading and the use of a digital signal processor that is usually required in other receivers. The proposed receiver architecture is chosen to satisfy requirements of hardware receivers used in high-speed QPSK communications. The receiver contains a receiver front-end, QPSK demodulator, and carrier recovery module. A reverse modulation loop was used to provide a rapid carrier recovery. The maximum bit rate is determined solely by the limiting speed of the baseband module. This new hardware receiver is proposed as a robust, rugged, low-cost receiver for use in wide Ka-band wireless mass-market QPSK communications such as local multipoint distribution system services, which is a prime example of communication equipment requiring such receivers. Bit-error-rate results are presented versus the noise and reference signal phase shift.

New-Wave Radio

Radio communications in the past century have relied primarily on nonlinear devices to modulate and demodulate signals for wireless transmissions. This article reviews initial laboratory results obtained with new radios using linear interferometers to modulate and demodulate ultra-wide-band (UWB) signals. Automotive and chip fabrication industries apply such interferometers in new commercial radios for UWB communications.

COMPARATIVE DEMODULATION RESULTS FOR SIX-PORT AND CONVENTIONAL 60 GHZ DIRECT CONVERSION RECEIVERS

Two 60 GHz homodyne receivers dedicated for high-speed short-range communication systems are presented. The receivers are based on six-port and conventional (anti-parallel diodes) mixers, respectively. Comparative bit error rate results, function of local oscillator power, phase, and frequency shift over the operating bandwidth, are presented and discussed.

A Heterodyne Six-Port FMCW Radar Sensor Architecture Based on Beat Signal Phase Slope Techniques

A Heterodyne six-port FMCW collision avoidance radar sensor conflguration based on beat signal phase slope techniques is presented in this paper. Digital IF circuitry has been used in order to avoid problems related to DC ofiset and amplitude and phase imbalance. Simulations show that the velocity and range to the target is obtained simultaneously, with very good accuracy. Results are compared to other techniques and system architectures.

V-band multiport heterodyne receiver for high-speed communication systems

A V-band receiver using a MHMIC multiport circuit is presented in this paper. The millimeterwave frequency conversion is performed using a passive circuit, the multiport, and related power detectors, avoiding the conventional millimeter-wave active costly mixers. Basically, the multiport circuit is an additive mixer in which the resulting sum of millimeter-wave signals is nonlinearly processed using millimeter-wave power detectors. This multiport heterodyne receiver is an excellent candidate for the future low-cost high-speed millimeter-wave wireless communication systems. The operating principle of the proposed heterodyne receiver and demodulation results of high-speed MPSK/QAM signals are presented and discussed in this paper. According to suggested datarate of 100–400 Mbps used to prove the operating principle, the IF of this receiver was chosen at 900 MHz. Therefore, this receiver is a possible alternative solution for WPAN applications