A dual six-port automatic network analyzer incorporating abiphase-bimodulation element

Current state-of-the-art dual six-port automatic network analyzers (ANAs) are dependent upon mechanical phase shifters and attenuators. Slow measurement and calibration are among the factors that have prevented six-port ANAs from more general use outside standards and research laboratories. Biphase bimodulation, a technique which removes the requirements for mechanical phase shifters or attenuators, is introduced. The technique provides improved sensitivity and elimination of drift as a consequence of AC modulation. A significant increase in measurement speed is achieved, allowing quasi-real-time evaluation of scattering parameters. An experimental prototype dual six-port ANA is described, and results obtained using the technique are given     

Multilayer Substrate Integrated Waveguide Six-Port Circuit

In this paper a new design of a six-port circuit based on multilayer substrate integrated waveguides (SIW) is presented. This design is based on the use of a multilayer structure aimed at reducing the dimension of the circuit while conserving the performances of the component. The designed SIW six-port is composed of two basic elements, a SIW power divider and directional coupler. These two elements are designed, optimized and matched to produce a better performance at the required operating frequency of 11 GHz. The results of simulations show that the new multilayer SIW six-port circuit has good performances including a good return loss and isolation under–20 dB and the transmission magnitude better than–10 dB. This multilayer SIW six-port has the advantage of a small size 160-34.8 mm; its width is about 50% smaller than the planar SIW six-port circuit, which helps to get a higher density of integration in telecommunication systems and allows much smaller devices to be conceived.A microstrip toSIWtransition is used in order to facilitate the integration of this component into other planar circuits. The structures are designed, simulated and optimized using the Ansoft HFSS simulation software.     

Dual-tone calibration of six-port junction and its application tothe six-port direct digital millimetric receiver

This paper describes a novel dual-tone calibration technique of a six-port using two carriers with closely spaced frequencies. The samples for the calibration are extracted from outputs of four power detectors using a self-adaptive algorithm. The calibration procedure is fully automatic and can be implemented in a system capable of capturing the output waveforms of a six-port. Although the proposed method is applicable to general six-port calibrations, it finds itself particularly suitable for the calibration of a new six-port direct digital MM-wave receiver. It is shown that such a calibration of the digital receiver can be fulfilled on site simply by receiving usual incoming signals. Dual-tone calibrations made at 26.5 GHz, 33 GHz, and 40 GHz demonstrate the same order of accuracy as the conventional six-port calibrations. However, the new technique is much simpler and faster as it requires less effort in its implementation     

An Ideal Six-Port Network Consisting of a Matched Reciprocal Lossless Five-Port and a Perfect Directional Coupler

A six-port consisting of a matched reciprocal Iossless five-port in series with a perfect directional coupler is shown to have ideal six-port properties according to the theory developed by Engen. The q points are separated by 120° on a common circle. The matched five-port itself is shown to function as a four-way divider network and bears an interesting analogy with a matched nonreciprocal Iossless three-port (circulator). This analogy is used to design several styles of matched symmetrical stripline five-ports for use in making six-port measurements.     

The Six-Port Reflectometer: An Alternative Network Analyzer

Although the six-port measurement technique is rapidly gaining the attention of the microwave community, the theoretical development, to date, yields but limited practical insight into its operation. Following a brief review of the prior art, such that the six-port techniques may be placed in proper perspective, this paper presents an alternative introduction leading to much better insight, and to design criteria for a six-port circuit which optimally exploits the concept.     

Measurement and calibration of a universal six-port networkanalyzer

A general theory of measuring multiport networks is presented. In order to measure microwave multiport networks conveniently a method involving the stepwise reduction of the order of the network under test is suggested. All formulas for calibrating and measuring the triple six-port network analyzer, which is a universal six-port network analyzer, are given without any ambiguity. The procedures for calibration and measurement are very simple. No standard three-port network is needed to calibrate the six-port system. Finally, the error caused by nonideal isolation is discussed     

Improved six-port circuit for complex reflection coefficient measurements

A new improved six-port circuit for complex reflection coefficient measurements is presented. It consists of two six-port directional couplers. Assuming the components to be ideal, it is shown that the described six-port circuit has optimal properties for accurate determination of complex reflection coefficients. A six-port branchline coupler is briefly described.     

用六端口和开口同轴线测量介电常数的一种校准方法

本文提出了一种六端口测量介电常数的校准方法，该方法将六端口和开口同轴线两次校准合为一次，特别适合于介电系数的在线测量。     

Planar lightwave circuit six-port technique for optical measurements and characterizations

The six-port approach is a well-established technique at microwave frequencies, where it has been extensively used as a simple and accurate means to measure complex reflection coefficients with a simple setup. However, its possible application at optical frequencies has not been sufficiently investigated. In this paper, a simple architecture to construct an optical six-port with a planar lightwave circuit (PLC) based on multimode interference (MMI) couplers is proposed for the first time. The proposed PLC is simulated, and the obtained results show a promising performance of the circuit in a wide wavelength range. This novel architecture will allow, in the near future, extending the successful six-port measurement technique up to optical frequencies.     

Millimetric network analyser using a single six-port reflectometer

An automatic network analyser is presented which uses a single six-port reflectometer in the W frequency band (75-110 GHz); its analysis, design, and testing are described. Also, a calibration procedure requiring two standards is used. Finally, some experimental results performed by the six-port analyser are presented.<>     

Réalisation ďun Réflectomètre a Six Accès Dans la Bande de Fréquences Millimétriques W (75-110 GHz)

This paper presents a six-port reflectometer in the W frequency band (75-110 GHz). Schottky diodes, operating in AC detection mode, are used as power detectors. A linearization procedure is used to improve the measurement accuracy. The six-port calibration is performed with two standards. Finally, the experimental results are compared with those obtained with other network analyzers in this frequency band.     

Finding initial estimates needed for the Engen method ofcalibrating single six-port reflectometers

It is shown how the initial estimates of the six-port to four-port reduction parameters needed for the Engen six-port calibration method can be found with a minimum of reflective terminations by using six-port parameters obtained by either of two previously published methods (U. Stumper, ibid., vol.37, p.222-30, 1989, or B. Neumeyer, Doctoral thesis, Technische Universitat Munchen, Munich, West Germany, 1989). With these methods, only five reflection values are needed, which can easily be realized by waveguide offset short-circuit reflection standards of different lengths, in the range of millimeter waves     

Quasi-circulator for effective cancellation of transmitter leakage signals in monostatic six-port radar

A quasi-circulator, composed of two branch-line couplers and an asymmetric power combiner, is proposed to effectively cancel the transmitter leakage signals in a monostatic six-port radar. The effective isolation is improved by 12.2 dB at 24 GHz. With the proposed quasi-circulator, the maximum detectable range of the six-port radar is improved by 167 , compared with that of the six-port radar with a conventional branch-line coupler.     

A Millimeter Wave Six-Port Network Using Half-Mode Substrate Integrated Waveguide

A novel six-port network based on half-mode substrate integrated waveguide (HMSIW) is proposed. In this design, a HMSIW hybrid 3 dB coupler and a -90° phase shifter are designed as fundamental building block of six-port network. By combining four HMSIW couplers and one phase shifter, a HMSIW six-port network at 29–32 GHz is constructed. The six-port network is fabricated and measured. Measurement results agree well with simulation, and show good balance and phase relationship between ports.     

功率计误差对六端口反射计精度影响的蒙特卡洛计算机模拟

功率计检测误差对六端口反射计的测量精度影响是非常大的。对于一个实际的反射计,由于整个系统比较复杂,用常规方法很难估算出功率计检测误差对反射计的测量精度的影响。本文引用了一种概率统计方法蒙特卡洛(Monte Carlo)法对六端口反射计的测量精度进行数值计算。并且用一个X波段的六端口反射计作为例子,给出了计算结果与直方图。用这种方法可以为六端口反射计的合理设计提供依据。     

Design,realization and performance of a millimetric six-port network analyzer

This paper presents the design, realization and performance of a six-port network analyzer in W frequency band (75–110 GHz). Schottky diodes operating in AC detection mode are used as power detectors. A new calibration method taking into consideration the imperfection components of the system, especially the flexible waveguide and the couplers is described. Finally, a comparison between experimental results performed with the six-port network analyzer and other measurement systems available in the W-band are presented.     

Six-port self-calibration based on active loads synthesis

An automatic method for self-calibrating six-port reflectometers is reported in this paper. It is based on the use of an active impedance synthesis system. This self-calibration method allows a completely autonomous operation, reduces measurement errors caused by the frequent connecting and disconnecting of calibration standards, and is suitable for low and high frequencies, where sliding shorts are difficult to manufacture. In addition, it simplifies operation of six-port reflectometers to nonspecialized users. The experimented impedance synthesis presented relies on an in-phase and quadrature vector modulator, and the entire system is computer controlled     

Simple derivation of six-port reflectometer equations

It is shown that the fundamental six-port equations can be obtained, almost by inspection, from a suitably normalised flow graph. The form of the six-port equations suited to most practical reflectometers is deduced.     

基于磁性光子晶体的多端口环行器设计

基于二维三角晶格和正方晶格光子晶体分别设计了六端口和八端口光子晶体环行器.环行器由硅介质柱光子晶体波导和铁氧体介质柱缺陷构成.所设计的六端口环行器每个波导连接处只有一个铁氧体材料,能够有效降低损耗;八端口环行器波导连接处添加了多个铁氧体材料可有效提高隔离度.使用有限元法对电磁波在环行器中的传输进行了仿真验证.计算结果表明,六端口环行器各端口的隔离度达到22～38 dB;八端口环行器各端口的隔离度达到21.7～40.5 dB.设计的多端口环行器具有结构简单紧凑、隔离度高、损耗低的优点.     

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.