Design of a Low-loss and High-SFDR Microwave Sampler

This paper proposes a microwave sampler operating at $\mathbf{2 - 1 0 G H z}$. The circuit is mainly composed of a pulse generation circuit and a sample and hold circuit. It uses a $\mathbf{2 - 3 G H z}$ high frequency local oscillator(LO) signal to directly drive a step recovery diode to generate a narrow pulse signal for sampling. Compared with the traditional low frequency LO signal sampling scheme, this design improves the sampling effect of high frequency RF signals by using a high frequency LO signal, and generates a larger intermediate frequency(IF) signal. The simulation and test results show that the conversion loss is better than -15 dB within the IF output frequency range of less than 30 MHz, and the SFDR can reach more than 35 dBc.