D. Hammou

Ring-Shaped Substrate Integrated Waveguide Wilkinson Power Dividers/Combiners

This paper proposes and presents a class of substrate integrated waveguide (SIW) power dividers/combiners based on a modified Wilkinson architecture. The proposed design consists of a ring-type circuit of 1.5 λg length with three waveguide ports. Impedance variation without affecting cutoff frequency and integration of isolation resistance are the two major limitations in connection with the design of SIW Wilkinson structures. Central ring part with different thickness ensures different impedance in the first proposed scheme while the half-mode SIW in the second option. As for the second limitation, the optimal configuration of integrating the isolation resistance is studied. A version without resistance is also examined using a broad-wall series slot. To validate the proposed concept, a bilayered circuit with standard Printed circuit board prototype was fabricated and measured. A table summarizing performances of all the proposed circuits shows a bandwidth of around 25% at the 10 dB reference. A negligible additional insertion loss is observed. The proposed design techniques are found useful at millimeter-wave frequencies where reduced physical dimensions make a circuit configuration suitable for low-cost implementation. This concept is also valid for rectangular waveguide counterparts.

V-Band Microstrip to Standard Rectangular Waveguide Transition Using a Substrate Integrated Waveguide (SIW)

In order to perform robust millimeter-wave S parameter measurements of integrated circuits, and to connect them to standard measurement equipment, a transition from microstrip to the WR 12 standard rectangular waveguide is requested. This paper proposes a new millimeter-wave microstrip to the standard WR 12 rectangular waveguide (RWG) transition by the bias of an intermediary Substrate Integrated Waveguide (SIW). The SIW technology allows wide-band and high performance circuit fabrication and enables robust transition between planar integrated circuits and standard waveguides. Commercial Finite Element Method Software, High Frequency Structure Simulator (HFSS) was used to perform the design and the optimization in term of return and insertion loss.

Complete characterization of novel MHMICs for v-band communication systems

This paper presents the characterization results of several new passive millimeter wave circuits integrated on very thin ceramic substrate. The work is focused on the design and characterization of a novel rounded Wilkinson power divider, a 90° hybrid coupler, a rat-race coupler, and a novel six-port (multiport) circuit. Measurements show the wideband characteristics, allowing therefore their use for multi-Gb/s V-band wireless communication systems.

V-band Six-Port Down-conversion Techniques

This paper presents comparative down-conversion results using two different topologies. The conventional approach using anti-parallel diodes acting as LO-driven switches is compared with the six-port one. The proposed down-converter which provides an intermediate frequency of 900 MHz uses a six-port circuit and two pairs of parallel Schottky diodes acting as power detectors connected to two differentials amplifiers. Simulation results of down-converter passive circuits in terms of I/Q IF power and phase are presented and discussed. In addition, comparative analyses are performed in terms of local oscillator and RF power required for the frequency conversion and phase stability. These results show the advantages of the proposed frequency conversion six-port technique.

MHMICs on ceramic substrate for advanced millimeter wave systems

This paper presents the initial design and fabrication results of several new passive millimeter wave circuits integrated on a thin ceramic substrate, having a relative permittivity of 9.9 and a thickness of 127 µm. The work is focused on a Wilkinson power divider, a 90° hybrid coupler, a rate-race coupler and two six-port circuits. Experimental results show wideband characteristics over the millimeter wave V and W bands, allowing therefore their use for high data-rate wireless communication systems and radar sensors.

MODIFIED MILLIMETER-WAVE WILKINSON POWER DIVIDER FOR ANTENNA FEEDING NETWORKS

This paper outlines typical issues in the design and fabrication of microstrip Wilkinson power dividers. As a practical solution, a modifled Wilkinson divider conflguration is proposed and designed for millimeter-wave antenna feeding networks. In this design, all microstrip branches and the resistive strip exhibit the same characteristic impedance. Probe measurements of S-parameters underline good matching, transmission and isolation characteristics of the proposed divider.

Novel MHMIC millimeter wave power divider/combiner

This paper presents a novel ring power divider/combiner operating in the 60 GHz band. The circuit is integrated on a thin ceramic substrate, having a relative permittivity of 9.9 and a thickness of 127 μm. The agreement between scattering parameter measurements and simulations ensures very good RF performance and manufacturability. The measured transmission magnitudes are less than 3.5 dB, while the overall imbalance is less than 0.25 dB. In addition, the matching of all ports is less than −15 dB, and the measured isolation factor between the two output ports is at least 25 dB. The measured transmission phase imbalance is less than 2.2° over the whole 10 GHz of bandwidth.

Modeling and Analysis of a Modified V-Band MHMIC Six-Port Circuit

This paper presents a modified V-band six-port circuit built on thin alumina substrate. This circuit is implemented using a rat-race and three 90° hybrid couplers. The S parameter measurements of both couplers show wideband performances and high coupled-port phase and amplitude balance in the 57 GHz to 64 GHz frequency band, corresponding to the IEEE 802.15.3c industrial standard. Therefore, the proposed six-port exhibits good phase and amplitude balance, while maintaining a good return loss. The proposed circuits are suitable for V band high data-rate communications systems.

Bi-layered substrate integrated waveguide Wilkinson power divider/combiner

This paper proposes a novel substrate integrated waveguide (SIW) power divider and combiner based on a modified Wilkinson architecture. This topology allows SIW waveguide to use conserving then shielding quality. The proposed design consists on a ring circuit of 1.5 λg length with three waveguide accesses. The optimal configuration of inserting the resistance is studied. A bi-layered circuit is fabricated with standard PCB process. Output return loss and isolation measurement results better than -10 dB are observed across around 25 % bandwidth over X-band (8.5 GHz to 11 GHz).

New V-band MHMIC six-port architecture

This paper presents a new V-band MHMIC six-port architecture built on thin alumina substrate. This circuit is implemented using three 90° hybrid couplers and a new ring power divider. The S parameter measurements of the new ring power divider show wideband performances and high coupled-port phase and amplitude balance in the 57–64 GHz frequency band. The proposed six-port exhibits good phase and amplitude balance, while maintaining a good return loss. The proposed circuits are suitable for unlicensed indoor V-band high data-rate communications systems according to FCC standard.