We have developed a low-noise 850 GHz superconductor–insulator–superconductor quasiparticle mixer with NbTiN thin-film microstrip tuning circuits and hybrid Nb/AlN/NbTiN tunnel junctions. The mixer uses a quasioptical configuration with a planar twin-slot antenna feeding a two-junction tuning circuit. At 798 GHz, we measured an uncorrected double-sideband receiver noise temperature of TRX5260 K...

In 1966 Barnette introduced a set of graphs, called circuit graphs, which are obtained from 3-connected planar graphs by deleting a vertex. Circuit graphs and 3-connected planar graphs share many interesting properties which are not satisfied by general 2-connected planar graphs. Circuit graphs have nice closure properties which make them easier to deal with than 3-connected planar graphs for s...

In this work, the analysis and design of wideband microstrip yagi and bi-yagi antenna arrays with photonic band gap (PBG) is presented. By using the bi-yagi planar array, a high directive gain and a high front-to-back ratio are achieved in comparison with that of the single microstrip yagi structure. The current distribution, return loss, radiation pattern, and input impedance are calculated. F...

This work presents the fastest Current Mode Logic static frequency divider to date. The circuit is fabricated in a commercially available InP process. Microwave techniques are used to achieve speeds of 75 GHz without resort to emitter followers. Interconnect design is stressed and the results of several variations are presented. Microstrip, inverted microstrip, peaking inductors and keep-alive ...

In this paper, S-shape microstrip patch antenna is investigated for wideband operation using circuit theory concept based on modal expansion cavity model. It is found that the antenna resonates at 2.62 GHz. The bandwidth of the S-shape microstrip patch antenna 21.62 % (theoretical) and 20.49% (simulated). The theoretical results are compared with IE3D simulation as well as reported experimental...

The utility and attractiveness of microstrip antennas has made it ever more important to find ways to precisely determine the radiation patterns of these antennas. Taking benefit of the added processing power of today’s computers, electromagnetic simulators are emerging to perform both planar and 3D analysis of high-frequency structures. One such tool studied was IE3D, which is a program that u...