Advantest U3661 9KHz to 26.5GHz Spectrum Analyzer

The Advantest U3661 is a portable microwave spectrum analyzer spanning 9 kHz to 26.5 GHz, engineered for field maintenance and signal analysis in microwave communications and TV broadcast relay applications. Its compact form factor - 148 mm × 291 mm × 330 mm, weighing 8 kg - combined with battery operation (up to 1.5 hours) and dual AC/DC power inputs, delivers measurement capability where facility power is unavailable.

Technical Specifications

Frequency & Resolution

• Frequency range: 9 kHz to 26.5 GHz


• Resolution bandwidth: 1 kHz to 3 MHz standard; optional 100 Hz and 300 Hz narrow IF filters; 5 MHz in Zero Span mode with option 26


• Sweep time: 50 µs fast sweep; 50 µs high-speed sweep in Zero Span mode Signal Measurement


• Displayed average noise level (DANL): –132 dBm with preamplifier


• Phase noise (SSB): –105 dBc/Hz to 3 GHz; –100 dBc/Hz at 10 kHz offset


• Dynamic range: 100 dB


• Total level error: 1 dB


• Amplitude range: +30 dBm to average display noise level


• Maximum input level: +27 dBm


• Integrated preamplifier gain: >25 dB (to 3 GHz) Demodulation & Analysis


• AM and FM demodulators


• Frequency counter: 1 Hz resolution


• Markers: up to six per screen


• Measurement functions: adjacent channel power (ACP), occupied bandwidth (OBW), spurious emission, adjacent-channel leakage power, total power measurement for spread spectrum signals


• Optional CDMA measurement functions; optional TV signal receiver/demodulator capability


• Optional tracking generator: 2.2 GHz (2.7 GHz with option 74), output –31 to 0 dBm in 1 dB steps


• Optional SWR bridge Display & Storage


• 6-inch color TFT LCD display


• Two PCMCIA card drives for measurement results and settings Interfaces

RS-232, GPIB, 10 MHz frequency reference input, external trigger, gate input, external DC input, video output. Optional TV video/audio input and output (option 72). Power Supply

• AC: 100/200 VAC


• External DC: +10 to +16 VDC


• Battery: up to 1.5 hours (standard); 1 hour (specialized); 2-hour recharge cycle

Key Features

• Field-portable design with battery independence


• Low noise floor suitable for weak signal detection


• Rapid measurement sweep capability


• Integrated preamplification for enhanced sensitivity


• Modular options for specialized applications (CDMA, TV, tracking generation, SWR)

Typical Applications

• Microwave communications system commissioning and maintenance


• TV broadcast relay facility inspection


• Signal presence verification and interference identification


• Spurious emission compliance verification


• Spread spectrum signal analysis

Compatibility & Integration Standard laboratory interfaces (RS-232, GPIB) enable integration with automated test systems. External frequency reference and trigger inputs support synchronized multi-instrument setups. TV signal interfaces (optional) support broadcast transmission quality assessment.