Phase-Locked Coaxial Resonator Oscillator (PLCRO)

Model PLOA or PLOD:


  • Output frequencies from 0.5 to 3 GHz

  • Very low phase noise

  • Internal or external frequency reference

  • Small size (2.25" x 2.25" x 0.62")

  • Low cost



This is a line of very low phase noise, fixed frequency phase-locked oscillators. A High-Q coaxial resonator oscillator and either analog sampling phase detector techniques (Luff model PLOA) or digital techniques (Luff model PLOD) are used to establish phase lock to a reference frequency.

The PLOA configuration is used when the best possible spectral quality is needed.  The PLOA configuration has the limitation that the output frequency must be an integer factor of the input frequency.

The PLOD has a much more flexible frequency plan, however, the phase noise of the PLOD is not as low as that of the PLOA.

Both units are housed in a rugged low profile assembly and employ our unique manufacturing techniques that result in units of excellent value.

Block Diagram




PLCRO Key Specifications

Output Frequency: from 500 MHz to 3 GHz
Spurious: -70 dB
Harmonics (typ.): -40 dBc
Output Power (min.): +13 dBm
Output Power Variation: 2 dB
External Reference: 1 to 200 MHz (0 dBm 3 dB)
or Internal Reference: 0.5 PPM (-10C to +70C)
Alarm: Open Collector or TTL

Power Requirements: 

+5.5 Vdc 0.5 V @ 250 mA

Size: 2.25" x 2.25" x 0.62"

Sample Product Data Sheets

    1 GHz Analog PLO - 10 MHz external reference input

      Model: PLOA1000-10

    1 GHz Digital PLO - 10 MHz external reference input

      Model: PLOD1000-10

Phase Noise Plot