The dynamic range tester: A versatile laboratory instrument for generating two highly isolated RF signals, each with variable signal-to-noise ratio

The Dynamic Range Tester (DRT) is a dual-channel, variable signal-to-noise ratio (S/N) generator that operates in the radio frequency (rf) range (30-400 MHz) [1]. It is a convenient tool for generating two highly isolated, noisy test signals from a single signal source, in order to simulate two antennas receiving the same signals. The DRT can also process two different signals, one in each channel, in order to simulate two antennas receiving different signals. According to the selected configuration, the DRT combines the user-supplied signal(s) with internally generated noise in two separate channels. Each channel of the DRT generates wideband, random noise that is uncorrelated and isolated from the noise in the other channel by approximately 90 dB. The maximum output power is 1 W (+30 dBm) signal and 1 W noise for a 20-MHz bandwidth. The signal(s) and noise power levels may be incrementally and individually varied to generate test signals with specific S/Ns from +80 dB to -80 dB. Using both outputs of the DRT, correlator processing gains of up to 160 dB can be evaluated since correlation is multiplicative. The frequency range and bandwidth of the generated signals are limited by selecting from a bank of filters or connecting an external filter in each channel. The DRT is used for a variety of testing and demonstration purposes, including determination of dynamic range of an rf system, frequency resolution of a correlator or spectrum analyzer, and interference and bandwidth testing