Basic RF Attenuator Circuit
Created: Aug 11, 2016
No description available.
There are different design of RF attenuator circuitry, but this design features a voltage controlled RF attenuator. It uses CPINU5208-HF pin diode that has very low series resistance and low capacitance ideal for RF application like two-way radios. It has power dissipation 300mW and 35V reverse voltage.
The pin diodes used in this design are used to achieved maximum attenuation at a minimum Vin. It is voltage controlled RF attenuator that able to control the level of a radio frequency signal using a control voltage. The supply V+ turns the diodes D1 and D2 on effectively shorting the signal to ground while the D3 is then reversed biased. The diodes D1 and D2 become reverse biased when Vin is increased and D3 becomes forward biased, allowing the signal to pass through the circuit. The capacitor values are dependent to the application/s in which it is the designed, therefore those values are not assigned the same thing with inductor L1. The resistors are assigned, which is based on typical values that are used in RF attenuator circuit. The inductor L1 along with the along with the capacitors C4 and C5 are included to prevent signal leakage from D1 to D2 that would impair the performance of the circuit.
This design circuit is applicable for experiments and development of RF products. It is also a good reference for the different designs of RF attenuator circuitry.