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Full-Text Articles in Systems and Communications
Wideband Voltage Variable Attenuator With Fewer Components, Chin-Leong Lim
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 …
Vva Extends Bw And Dynamic Range, Chin-Leong Lim
Vva Extends Bw And Dynamic Range, Chin-Leong Lim
Chin-Leong Lim
Voltage-variable attenuators (VVAs) enable gain adjustment in a wide range of applications, including in cable-television (CATV), satellite-television (SATV) systems, and even test equipment and measurement systems. The PI VVA configuration using PIN diodes is ubiquitous in CATV and SATV systems owing to its low part count, small size, constant impedance, high linearity, and multi-decade bandwidth. Presently, this class of VVAs have been under severe miniaturization pressure in order to shrink end-product size. To create the industry's smallest CATV/SATV-suitable VVA, we integrated all necessary components into a multi-chip-on-board (MCOB) package measuring 3.8 x 3.8 x 1.0 mm (14 mm square footprint). …