Broadband Microwave System Amplifiers vs. Benchtop Instrumentation Amplifiers

System amplifiers, such as the Keysight Technologies (Agilent HP) 83050A, Keysight Technologies (Agilent HP) 83020A, and Keysight Technologies (Agilent HP) 83051A, are engineered to minimize space and weight within system enclosures. For example, the Keysight Technologies (Agilent HP) 83050A has compact dimensions of 45 mm × 45 mm × 114 mm and weighs 0.64 kg. To achieve this density, system amplifiers omit internal AC-to-DC power supplies, relying instead on external DC bias inputs (such as +12 VDC and -12 VDC for the 83050A and 83051A, or +15 VDC and -15 VDC for the 83020A).

In contrast, benchtop instrumentation amplifiers, like the Keysight Technologies (Agilent HP) 8347A, are fully self-contained instruments. The Keysight Technologies (Agilent HP) 8347A operates directly from standard AC lines (100 to 240 VAC, 48 to 66 Hz). This internal power conversion increases physical size (213 mm × 102 mm × 297 mm) and weight (3.6 kg), but makes the unit highly portable and ready for standalone work on a lab bench without external power-supply accessories.

System amplifiers are frequently optimized for ultra-broadband microwave spans to handle high-frequency routing and system loss recovery. The Keysight Technologies (Agilent HP) 83051A preamplifier, for instance, operates from 45 MHz to 50 GHz, while the Keysight Technologies (Agilent HP) 83050A operates from 2 to 50 GHz. These modules are placed strategically in the signal path to compensate for coaxial cable losses or switch matrix attenuation.

Benchtop units often target lower-frequency RF ranges or specific multi-octave bands where general-purpose stimulus and measurement dynamics are needed. The Keysight Technologies (Agilent HP) 8347A operates from 100 kHz to 3 GHz, offering gain flatness of ±1.5 dB over its primary range (10 MHz to 3 GHz) to act as a stable source booster. For microwave power applications, solid-state models like the Giga-tronics GT-1000B cover 100 MHz to 20 GHz, providing wideband coverage in a standalone chassis configuration.

Choosing between these formats also impacts the amplification profile. System power amplifiers, such as the Keysight Technologies (Agilent HP) 83020A, are capable of delivering significant power (minimum output power at 1 dB compression of +30 dBm or 1.0 W from 2.0 to 20.0 GHz) to boost signals inside a rack. System preamplifiers like the Keysight Technologies (Agilent HP) 83051A prioritize signal recovery, offering a minimum small signal gain of 23 dB and noise figures under 12 dB up to 26.5 GHz.

Benchtop models balance noise and power for general instrumentation duties. The Keysight Technologies (Agilent HP) 8347A provides a nominal gain of at least 25 dB (10 MHz to 3 GHz) and an output power at 1 dB compression of at least +20 dBm, suitable for general-purpose bench measurements where high-frequency sub-components are characterized.