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Wideband Voltage Variable Attenuator With Fewer Components, Chin-Leong Lim

Chin-Leong Lim

RF/microwave amplifying devices have unit-to-unit gain variability. So, in some critical applications such as the low noise amplifier (LNA) in cellular basestations, the gain has to be adjusted in production using a voltage-variable attenuators (VVA). Constant impedance VVAs such as the PI and the bridged-TEE topologies require between 14 to 18 components, including 2 to 4 active devices, but their large dynamic (attenuation) range is wasted in this amplifier gain adjustment application. To create a more economical and smaller VVA for amplifier gain adjustment, we investigated a new circuit configuration comprising one active and four passive components. This paper describes …