Ultra-wideband balanced schottky envelope detector for data communication with high bitrate to carrier frequency ratio

This paper reports on an ultra-wideband (UWB) Schottky diode based balanced envelope detector for the L-, S-, C- and X- bands. The proposed circuit consists of a balun that splits the input signal into two 180° out of phase signals, a balanced detector, that demodulates the two signals, a low pass filter that rejects the second harmonic spurious from the Schottky diode and a bias tee that selects the optimum rectification point. The manufactured prototype is able to demodulate error free a 4 Gbps amplitude shift keying (ASK) signal at 4 GHz carrier frequency, leading to a record bitrate to frequency carrier ratio (Δb) of 100%. Besides this, the detector achieves error free demodulation for carrier frequencies between 4 and 8 GHz, while keeping the bitrate at 4 Gbps.