15 dB conversion gain, 20 MHz carrier frequency AM receiver in flexible a-IGZO TFT technology with textile antennas

This paper presents an AM receiver implemented in a flexible a-IGZO TFT technology. The circuit consists of a four-stage cascode amplifier at the RF input, a detector based on a source follower, and a common source circuit for the baseband amplification. The measured conversion gain is very flat and exceeds 15 dB from 2 to 20 MHz carrier frequency range, which covers a relevant portion of the shortwave radio band. The 3 dB-bandwidth of the audio signal is 400 Hz to 10 kHz, which is comparable to the so-called voice band, and it is also suitable to low-rate data communication. In addition, an integrated demonstration of the AM receiver and textile antennas is carried out. The flexible a-IGZO receiver successfully detected the baseband signal through the textile antennas, demonstrating for the first time wireless transmission for this class of technologies.