Multi-Function Patch Element

Abstract

Abstract-Integration of multiple functions is for the first time achieved within a single patch circuit element. Firstly, out of phase equal power division and bandpass filter characteristics are combined within a patch element. The novelty of the proposed structure is to use simple asymmetric cross slots in the patch element to achieve this integration. A simplified equivalent circuit model to describe operation of this patch element is proposed. Coplanar waveguide/microstrip broadside coupling is then investigated to enhance the performance of the patch balun filter and eliminate narrow coupling gaps and microstrip lines. Subsequently, transition between microstrip and coplanar waveguide is then added to the patch element by using certain electromagnetic coupling methods for higher level integration without introducing additional loss. Different patch elements operating at 2.4 GHz are developed to validate the feasibility of the proposed structures. The circuits were designed, fabricated and measured. The measured results agree quite well with the simulation, exhibiting small amplitude and phase imbalance at the output ports throughout the desired passband, and good rejection levels elsewhere.

Tunable dual‐mode microstrip patch resonators and filters

“…In the designs of microstrip BPFs, dual-mode resonators with ring, loop and patch structures are more attractive because of their half-reduced number of resonators and compact filter configurations, compared with single-mode resonators [4][5][6][7][8][9][10][11][12][13]. The BPFs designed by using dual-mode patch resonators show higher power-handling capability than those using ring or loop resonators [8][9][10][11][12][13]. Lots of effort has been done for tunable single-mode patch resonators [3] and for dual-mode ring or loop resonators [4][5][6].…”

Multifolded Bandwidth Branch Line Coupler With Filtering Characteristic Using Coupled Port Feeding

“…Circuit integration is a straightforward approach in resolving the above problems with the concept already demonstrated with balun filters [16][17][18][19][20] which combine out of phase power division with bandpass filtering function. The coupler filter proposed by Uysal and Watkins [21,22], made by non-uniform transmission lines had a relative bandwidth of 18% but occupied an area of more than 2-wavelengths by 5-wavelengths at the center frequency.…”