A 27-MHz frequency shift keying wireless system resilient to in-band interference for wireless sensing applications

<span lang="EN-US">A 27-MHz wireless system with binary frequency shift keying (BFSK) modulation at 400-kHz is reported. The receiver has been designed to handle in-band interference corrupting the BFSK signal use of complex filters and amplitude comparison method. carried out a voltage-controlled oscillator before up-converting local oscillator. bipolar junction transistors (BJT-based) power amplifier 30% efficiency pumps 220 mW into spiral antenna. inductive-degenerated low-noise voltage more than 30 dB amplifies an incoming feeding mixer for direct down conversion. With deliberate Gaussian injection, minimum ratios between only distance 2.5, 10 15 m are 3.3, 8.5 11.5 dB, respectively maximum data rate 20 kbps. Without any included, can achieve 40 kbps transmission m. Conceptually agreed presented bit-error-rate (BER) analysis, BER measurements single-tone/two-tone interferences also confirm superiority offered by method where signal-to-noise ratio 1 BER=10<sup>-3</sup> (10 better phase detection counterpart).</span>