Microstrip line to waveguide transition with quarter-wavelength open stubs

Abstract

It is desirable for microstrip line/waveguide (MSL/WG) transitions to have low-loss, low-cost, and high-reliability. In order to suppress the unnecessary radiation which is a cause of loss, through-holes are provided in conventional transitions to surround the connection section. However, if through-holes are provided, manufacturing cost increases due to the greater complexity of the manufacturing process. In addition, since the dielectric expands and contracts due changes in temperature, problems arise involving decreased reliability, such as wire breakage due to application of tension to through-holes. Thus, this paper concerns a MSL/WG transition which simultaneously realizes low-loss, low-cost, and high-reliability by using a quarter-wavelength wavelength open stub instead of through-holes.