2차 고조파 최소화를 위한 광대역 중간주파수신기 개발

Abstract

In this study, an eight-channel wide-band intermediate frequency (IF) receiver with an S-band input frequency, an output frequency of 200 MHz, and a signal bandwidth of 160 MHz was developed. The performance measurement results of the IF receiver showed that the fundamental signal and the second harmonic signal were involved in the bandwidth of the IF receiver output. This was caused by the nonlinearity characteristics of the final stage amplifier. Therefore, the final stage amplifier was changed to a differential amplifier, and the circuit of the IF receiver was modified to reduce the second harmonic signal. After improvement, an IF receiver with a gain of 33 dB, Output 1 dB Gain Compression Point(OP1dB) of > 15.8 dBm, 3rd Output Intercept Point(OIP3) of > 25.7 dBm was developed. The second harmonic suppressions were in the range of −83.30 dBc to −75.19 dBc when the fundamental signal output power was −10 dBm. This result satisfied the requirement of the system for the second harmonic suppression that was lower than −70 dBc.