Boost Supply and High-Voltage DAC Provide Tuning Signal for Antennas and Filters

Antenna arrays and filters are often tuned by varying the voltage on a barium strontium titanate capacitor. Voltages applied to this ferroelectric material cause small variations in the crystal structure, changing the dielectric constant and, thus, the capacitance. The capacitor is tuned by applying a voltage of up to 30 V. This article shows an easy way to generate a high-voltage tuning signal in a low-voltage system.