Active quasi-Yagi antenna direct conversion receiver array with digital beamforming

A four-element array single card receiver for indoor wireless applications at C-band is presented. A broadband quasi-Yagi antenna is adopted as the antenna array element due to its broad beamwidth and low mutual coupling characteristics. The integrated receiver circuit uses a multilayer architecture, where RF and baseband circuits are placed above and below the antenna substrate, resulting in a very compact design. Using digital signal processing, the array element patterns are calculated from the four-channel amplitude and phase information of the baseband outputs. An initial test of the integrated receiver shows a scanning range of 70/spl deg/, without the use of any adaptive algorithm.