The first step in meeting the challenge of a good, low cost aperture array is to have good, low-cost receivers. North-West University has developed a 0.5-1.5 GHz active receiver elements consisting of a single PCB that acts as both the antenna and low noise amplifier.
The output of the receivers are connected through a ground plane using coax cables:
These receivers has very good sensitivity in the 0.6 – 1.6 GHz band. The noise temperature is close to that of the ATF35143 transistor used and the effective area of a single element almost follow that of a dipole.
Each PCB cost about $30 and has 2 receivers, one for each polarisation direction. More detail about the receiver will be posted later.