1λ Spaced Dual Radiating Modes Based Phased Array Antenna Using Silicon RFICs With Grating Lobe Cancellation

A dual radiating modes (TM11 and TM21)-based phased array antenna with $1\lambda $ interelement spacing at Ku-band is demonstrated using silicon beamforming RFICs, which offers grating lobe cancellation. The radiating element consists of concentric microstrip circular patch antennas supporting TM11 and TM21 modes. Excitation of both modes (TM11 and TM21), with the proper amplitude and phase values, allows for the suppression of grating lobe present in the array radiation pattern. The array utilizes Anokiwave RFICs (AWMF-0117), which provides flat panel integration of the beamforming network with the antenna aperture. A suitable beamforming network consisting of wideband Wilkinson power dividers was used to feed the RFICs from a single input. We demonstrate a grating lobe suppression ability of up to 30.8 dB with a first sidelobe level (SLL) of 15.2 dB. We also confirm the grating lobe mitigation technique through the demonstration of an over-the-air (OTA) link using digitally modulated signals and observing the error vector magnitude (EVM) of the received signal.