Anyone have any experience using these BST capacitors for antenna tuning arrays, or tunable filters ?
:-) neil KE6DCJ
======== Powering a 30V DAC from a 3V supply (CN0193) Analog Devices Model Number: CN0193
The circuit generates a high voltage signal that controls the capacitance of a BST (barium strontium titanate) capacitor. The capacitance of a BST capacitor can be altered by applying a voltage of between 0 V and 30 V to the correct terminal. This changes the thickness of the dielectric and, hence, the capacitance.
BSTs are often used for tuning antenna arrays or tunable filters. Clearly, there is an advantage in being able to tune these applications for example, compensating for component tolerance errors. This reference circuit has been engineered and tested for quick and easy system integration.
Design note here: http://www.analog.com/static/imported-files/circuit_notes/CN0193.pdf