Spectrum analysis normally requires a heavy, rack-mount receiver with built-in filters, attenuators, and monitoring capabilities. The model FSH6 spectrum analyzer from Rohde & Schwarz (Columbia, MD) features all those components and more, but fits within a compact, handheld unit measuring just 170 × 120 × 270 mm and weighing a mere 2.5 kg. The instrument operates from 100 kHz to 6 GHz (or 100 kHz to 3 GHz as model FSH3) and includes a frequency counter with 1-Hz resolution and built-in tracking generator for scalar-analyzer measurements.
Both the 3-GHz model FSH3 and 6-GHz model FSH6 offer resolution bandwidths of 100 Hz, 300 Hz, 1 kHz, 3 kHz, 10 kHz, 30 kHz, 100 kHz, 200 kHz, 300 kHz, and 1 MHz and video bandwidths of 10 Hz to 1 MHz in a 1-3 sequence. The analyzers feature a 100-dB displayed dynamic range and amplitude reference levels can be set from 80 to +20 dBm in 1-dB steps. Sensitivity is limited only by a displayed average noise level of less than 105 dBm (typically 112 dBm) from 100 kHz to 3 GHz and less than 96 dBm through 6 GHz.
A preamplifier can be added to either analyzer to improve the noise floor to 120 dBm through 3 GHz and 105 dBm through 6 GHz. The analyzers derive their accuracy from a temperature-compensated crystal oscillator (TCXO) with 1 PPM/year aging rate and 2 PPM temperature drift from 0 to 30ºC. The analyzer single-sideband (SSB) phase noise is 85 dBc/Hz offset 30 kHz from a 500-MHz carrier and 120 dBc/Hz offset 1 MHz from the same carrier.
The battery-powered analyzers include a variety of detectors to capture signals, including auto peak, maximum peak, minimum peak, sample, and root-mean-square (RMS) detectors. The level measurement error is less than 1.5 dB and typically 0.5 dB. Sweep times can be set from 1 ms to 100 s over spans as wide as 6 GHz. Traces are shown on a 14-cm color liquid-crystal-display (LCD) screen with 320 × 240 pixels resolution.
Both analyzers include tracking generators for performing scalar-network-like measurements. Both analyzers are available with several options, including option FSH-K2 for distance-to-faultmeasurements over a range of 3 to 1000 m (with displays of return loss and VSWR), power sensors for measurements of levels from 200 pW to 200 mW (67 to +23 dBm), and an RS-232C interface. Rohde & Schwarz, Inc., 8661A Robert Fulton Dr., Columbia, MD 21046-2265; (410) 910-7800, (888) 837-8772, FAX: (410) 910-7931, e-mail: email@example.com, Internet: www.rohde-schwarz.com.