Shao Yong Zheng

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Previous hybrid couplers have output phase difference that have either been 0<sup>&#x00B0;</sup>, 90<sup>&#x00B0;</sup>, or 180<sup>&#x00B0;</sup>. Other phase differences could only be realized using additional phase-shift elements. This increased circuit size and cost, and also degraded overall performance due to interconnecting mismatch losses. The(More)
This paper presents, for the first time, the design of a rectangular patch hybrid coupler that can operate at two arbitrary frequency bands with the same quadrature phase relation between the two outputs. The design procedure of the hybrid coupler is presented. For demonstration, a dual-band rectangular patch hybrid coupler is designed to operate in the(More)
This paper presents, for the first time, the design of a size-reduced rectangular patch hybrid coupler. Different types of compact rectangular patch hybrid couplers with different ground plane patterns are described. For demonstration, two compact rectangular patch hybrid couplers are designed to operate at 3.5 GHz. They are measured to have 30.1% and 33.3%(More)
<?Pub Dtl?>This paper presents, for the first time, a patch coupler configuration that can be designed with an arbitrary coupling coefficient and phase difference at the output ports. Four circular sector patches are combined to form the patch coupler resulting in ease of design and fabrication. To demonstrate and verify this, a patch quadrature coupler(More)
This paper presents, for the first time, a method to realize the concept of frequency agility on patch-type circuits, which have found more applications at very high frequencies because of its simple structure. A patterned ground plane has recently been proposed for size reduction of patch-type circuits making them more favorable at lower frequencies. An(More)
Traditional two-way passive differential phase shifters (DPSs) are comprised of a reference line and a delay line. To realize a passive multi-way poly-phase DPS, a single reference line is not possible and a cascaded network becomes necessary. This results in both a cumbersome and complex structure, with large phase error that propagates through the(More)