Design of Edge-Coupled Microstrip Patches Filtenna

A microwave structure that combines filtering and radiating functions is presented. The structure consists of three patches, two of which are aperture-fed, printed on stacked substrates. The array can be considered as three-pole edge-coupled filter with radiating resonators. It can also be viewed as a two-port array antenna with frequency domain filtering capability. The array was designed to operate as three-pole band-pass filter with a fractional bandwidth of 5% at a midband frequency of 2.0 GHz. The proposed structure was simulated using CST (Computer Simulation Technology) software package and measured using HP8722D vector network analyzer. The structure exhibits filter-like frequency response with three reflection zeros observed in the return loss result. The measured and simulated 3- dB bandwidths are 117 and 130 MHz respectively. The structure also provides a well-shaped radiation pattern and good gain within the operating band.