A Millimeter Wave Microstrip Antenna Array with Harmonics Suppression Elements

Abstract

Antenna element and array with harmonic suppression ability are desired in compact and integrated RF front-end systems, because they can lead to remove the additional bandpass filter. This paper presents a microstrip antenna element with the operation frequency of 35 GHz. A good second order harmonic suppression performance is obtained by a compact co-planar structure. A 1times4 array constructed by this element is also studied. The antenna array is fed by a corporate-feed network without using quarter-wavelength impedance transformers. Element and array gain of 5.4 dB and 11.4 dB are achieved, respectively. Compared to the traditional antenna array, the studies indicate that the array obtains a gain suppression of 9.1 dB and 7.0 dB at the frequency of 46 GHz (corresponding to TMn of the reference antenna array) and the second order harmonic frequency of 70 GHz, respectively.