RF HIGH POWER SWITCH WITH REVERSE BIASED PIN-DIODES
Original Publication Date: 1994-Oct-01
Included in the Prior Art Database: 2002-Mar-11
Rfswitches often consist of PIN-diodes which are in a high impedance state while high rfpower is applied. Above a certain rf power level, the PIN- diode's change to a lower rf impedance range increases the dissipation loss and might further destroy the component. To prevent an impedance decrease caused by rf power the device has to be reverse biased. A conservative solution of selecting the bias is to avoid the rf magnitude to exceed the dc bias voltage. This requires high negative dc volt- ages which are costly and not always available, espe- cially in mobile or portable equipment. A so called conditional save operation can be achieved with a lower bias voltage only as high as the self-generated dc voltage ofthe PIN-diode. This voltage level which is dependent on the device type and the rf power level often still exceeds the available dc voltages.