The performance of unbiased balanced photodiodes for optical calibration of radio-frequency antenna arrays

The performance of unbiased balanced photodiodes has been measured for RF antenna array calibration. As opposed to a single unbiased photodiode, the unbiased balanced photodiodes suppress the photodiode-induced distortion and demonstrates a 26-dB increase in second-order output intercept point. This increase in intercept point translates to a 13-dB increase in spurious-free dynamic range for the second-order-limited link.