Six-port Receiver Research Articles

Adjacent channel suppression (ACS) in direct‐digital six‐port receivers

AbstractSystem simulation results of a digital six‐port receiver operating with an ideal six‐port (120° between Qi points), over two adjacent channels, are compared with a second six‐port receiver operating with a special six‐port circuit possessing 120° separation between Qi points in the receiving channel and 0° separation between Qi points in the adjacent channel. Theoretical analysis and simulation results are given on adjacent channel suppression using 64‐QAM modulation. The implementation of special six‐port ACS requires a six‐port wave structure with constant phase velocity in the receiving channel and reduced phase velocity in the adjacent channel to decrease the angles of the two adjacent Qi points of the six‐port by 120°. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 265–270, 2001.

A Bayesian network (BN) decoder for direct‐conversion microwave and millimeter‐wave six‐port receivers (SPRs)

AbstractIn this paper, learning algorithms are used to decode QPSK data in a direct‐conversion hardware (QPSK‐unimode) microwave/millimeter‐wave receiver using an application‐specific six‐port module. Two different algorithms, the K‐means and Bayesian network, are considered for operation of the decoder to recover IQ data from QPSK modulated signals. Bit‐error‐rate (BER) results versus noise level (Eb/N0) are presented after a brief data‐collecting period involving fewer than 500 data points. Results of the Bayesian network for Eb/N0=−3 dB and Eb/N0=−9 dB are presented, using the same data‐gathering period. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 33–38, 2001.

A new direct millimeter-wave six-port receiver

A new direct-conversion wide-band (23-31 GHz) six-port receiver is proposed suitable for millimeter-wave integrated system design. This new hardware receiver is found to be robust, rugged, low cost, and suitable for use in broad-band wireless mass-market QPSK communications. The prototype circuits are fabricated to validate this new concept with our miniaturized hybrid microwave integrated-circuit technology and the proposed receiver topology is also suitable for monolithic-microwave integrated-circuit fabrication. This application-specific integrated receiver is designed on the basis of a wide-band six-port junction and other analogical circuits in the form of a simple multichip module. Bit-error-rate measurements and simulation results are shown and discussed in the presence of noise, adjacent signal interference, local-oscillator (LO) phase shift, and LO phase noise. The maximum bit rate is fundamentally limited by the speed of the video and decoder circuits. Nevertheless, several hundred megabits per second can be achieved at low cost.

Six-Port Receiver and Frequency Measurement for Radar Applications at 35GHz

The application of a six-port technology in the receiving part of a radar front-end is described in this paper. This receiver allows measuring magnitude and phase of the radar signal without the need of down-conversion. According to the applications and the availability of the devices needed for assembling the prototype sensor, the frequency of operation was set to 35GHz. The structure of this six-port as well as the calibration and measurement algorithms are described in detail. The accuracy of the phase measurement is 2–10° depending on the power level of the signal. Another key element of the proposed radar sensor is a direct frequency counter. Using this circuit it is possible to measure the frequency of operation with a resolution of 20 bits within 120μs. The accuracy of the distance reading of the radar is directly related to the accuracy of the frequency measurement and has reached 0.1mm.

On the real-time calibration of a six-port receiver (SPR) by averaging the received QPSK signals

On the real-time calibration of a six-port receiver (SPR) by averaging the received QPSK signals

On the real-time calibration of six-port receivers (SPRs)

In this paper, a study of the simplification of real-time () calibration of six-port receiers SPRs is gien. A simple, real-time calibration procedure is proposed using the incoming QPSK signal as the calibration standard. Only two systems of four linear equations are necessary to be soled in the calculation of the calibration parameters. This calibration procedure is especially suitable for QPSK reception. Modulation errors will be cancelled if the receied signal is selected for the calibration standards. SPW simulation results of 64 QAM signal receptionalidate the proposed calibration procedure. Q 1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 20: 318)322, 1999.

On the real‐time calibration of six‐port receivers (SPRs)

On the real‐time calibration of six‐port receivers (SPRs)

Effects of local oscillator leakage in digital millimetric six-port receivers (SPRs)

5. CONCLUSIONS In conclusion, an Ni:LiNbO directional coupler at a wave- 3 length of 1.32 mm was fabricated successfully for the first time. In addition, the multiple waveguide array method was utilized to exactly measure the coupling coefficient k and coupling length L. Furthermore, our method focused on the c fabrication of directional coupler arrays instead of a linear wx array of waveguides 7 . From the experimental results shown, our method appears to be simple and accurate. ABSTRACT: In this paper, the problem of local oscillator LO leakage () to the input of a digital millimetric six-port receier SPR is studied in detail. It is shown that this leakage can be considered as an additional in-band interference signal to the SPR that alters the output signals of the six-port discriminator as if the Q points of the six-port junction are i modified. Analysis and simulation results of this leakage are proided, and methods to oercome its effects for real-time operation are gien. Improements in the performance of a six-port junction in the presence of LO leakage are ealuated. Q 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 19: 27)34, 1998.

On the nonlinear interference effect of six-port digital millimetric receiver and its suppression

On the nonlinear interference effect of six-port digital millimetric receiver and its suppression

Design and analysis off a six-port receiver for use in near-field antenna measurements

The configuration, analysis and calibration of a six-port based receiver for near-field antenna measurements is described. The receiver operates in an approximate manner in which the transmission coefficient is obtained from a single measurement. Design rules are given which keep the operational errors of the device smaller than those introduced by the approximations inherent in the near-field measurement theory. Tests show that the receiver is accurate and stable when operated in a dynamic range of approximately 50 dB. The suitability of the six-port receiver in near-field measurement systems is demonstrated through the measurement of radiation patterns of horn antennas.