Agilent/Keysight 11721A

The Agilent/Keysight 11721A is a passive frequency doubler accessory that extends the frequency coverage of signal generators, synthesizers, and RF sources by producing an output signal at twice the input frequency. Operating across 50 MHz to 1300 MHz input, it delivers 100 MHz to 2600 MHz output—enabling access to higher frequency bands without requiring a new source instrument.

– Technical Specifications

• Input Frequency Range: 50 MHz to 1300 MHz
• Output Frequency Range: 100 MHz to 2600 MHz
• Conversion Loss: <15 dB (50 to 1280 MHz at +13 dBm input)
• Spurious Performance: At +13 dBm input (50 to 1280 MHz, harmonics <−50 dBc)
– f/2: −15 dB
– 3f/2: −15 dB
• Input SWR: 1.5 (typical)
• Impedance: 50 ohms nominal (input/output)
• Operating Temperature: 0°C to +55°C
• Connectors: Type N male (input), Type N female (output)
• Dimensions: 161 mm × 30 mm × 20.5 mm (6.3" × 1.18" × 0.81")
• Weight: 181 g (6.4 oz)

– Key Features

• Passive design—no external power supply required
• Low conversion loss maintains signal integrity across the operating range
• Controlled spurious outputs ensure minimal interference
• Good input match (1.5 SWR) reduces source interaction effects
• Compact form factor integrates into benchtop and production test setups

– Typical Applications

• Extending synthesizer or signal generator frequency coverage into millimeter-wave test bands
• Harmonic generation for RF/microwave component characterization
• Doubler-based test configurations where discrete frequency multiplication is required

– Compatibility & Integration

The 11721A accepts RF input from any source producing signals in the 50 MHz to 1300 MHz range. Type N connectors on both ports support standard laboratory and production instrumentation. As an accessory product, it integrates with existing signal sources without modification.