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.
