مطالعه شبیه سازی در ویژگی های مسیر مسابقه حلقه ترکیبی 3 گیگاهرتز مایکرواستریپ

This paper theoretically analyzed the characteristics of the microstrip hybrid ring. 3 dB standard microstrip hybrid ring and racetrack hybrid ring, whose working frequency is 3 GHz, have been designed on a rectangular substrate. Using high frequency structure simulator (HFSS) software as tool for simulation, the s-parameter data is comparatively studied. The experimental results showed that the overall performance of the designed racetrack microstrip hybrid ring is superior to the ordinary standard microstrip hybrid ring.

Microwave hybrid ring is one of the most important passive components in microwave circuits and is widely used. Hybrid ring is composed by a circular transmission line and four branch lines. It is a typical 3 dB 180o directional coupler. Its main applications include the power divider, power combiner, balanced mixers, push-pull amplifier, standard phase shifters, antenna array feed network and so on [1–2]. Microstrip hybrid ring has gradually replaced the waveguide hybrid ring for its advantages of small size, light weight, easy processing. The main direction of the microstrip hybrid ring is broadband and miniaturization [3]. The standard shape of microstrip hybrid ring is shown as Fig. 1. The angle of the four branch line is 60 degrees, so the branch lines would be the turning corner, if the hybrid ring is designed on a rectangular substrate. And voltage standing wave ratio (VSWR) would be increased because of the turning corners. To overcome this shortcoming, a new microstrip hybrid ring named racetrack is designed, shown in Fig. 2. This paper theoretically analyzed the characteristics of the microstrip hybrid ring. 3 dB standard microstrip hybrid ring and racetrack hybrid ring, whose work frequency is 3 GHz, have been designed on a rectangular substrate. Using HFSS software as tool or simulation, the s-parameter data is comparatively studied.

Compared with the simulation results of the 3 GHz standard microstrip hybrid ring which is designed in the same conditions, the data indicators of the microstrip racetrack hybrid ring are equal to or better than the standard one’s, especially the VSWR is decreased by about 10%. Because of space limits, the simulation data of the 3 GHz standard microstrip hybrid ring is not listed. But the geometry size of microstrip racetrack hybrid ring is slightly larger than the standard one’s, which limits its application to a certain extent.