Local Oscillators
& Synthesizers
The signal source that drives every frequency conversion chain. Phase locked oscillators, wideband synthesizers, voltage controlled oscillators, and mechanically tuned Gunn sources, custom-built from 8 GHz to 220 GHz to your exact phase noise, power, and frequency requirements.
Signal Source Products
Phase Locked Oscillators
The workhorse of every high-performance frequency converter chain. Our phase locked oscillators use a low-noise Gunn or GaAs FET source locked to a crystal or OCXO reference through a precision PLL. The result is an LO signal with the spectral purity required to meet tight sideband noise specifications in SATCOM ground terminals, radar receivers, and test instrumentation.
Every PLO is custom-built to your frequency. Whether you need a fixed 37.5 GHz LO for a Ka-band downconverter or a 94 GHz source for a W-band radar front end, we design the oscillator, multiplier chain, and filtering to deliver the output power and phase noise your system demands. Waveguide output interfaces from WR-28 through WR-05 and coaxial options are available.
Frequency Synthesizers
When your system requires frequency agility, a synthesizer replaces the fixed PLO with a programmable, digitally controlled signal source. Our synthesizer modules integrate a wideband VCO, fractional-N or integer-N PLL, reference distribution, and output amplification into a single shielded assembly. Serial or parallel digital interfaces allow frequency selection with sub-hertz resolution and microsecond switching speeds.
We build synthesizers covering DC to 110 GHz in single or multi-octave tuning ranges. Applications include multi-channel frequency converters where the LO must hop between transponder frequencies, electronic warfare receivers requiring fast-scan coverage, and automated test systems that step through frequency plans under software control. Each unit is built to your tuning range, step size, phase noise mask, and spurious specification.
Voltage Controlled Oscillators
The fundamental tunable element inside every PLL synthesizer and agile frequency converter. Our voltage controlled oscillators use Gunn diode, GaAs FET, or InP HEMT active devices depending on the target frequency and tuning bandwidth. The output frequency tracks a DC tuning voltage applied to a varactor or bias network, providing continuous analog frequency control across the specified tuning range.
VCOs are available as standalone modules for integration into your own PLL or as drop-in replacements for existing converter LO stages. We build VCOs from 8 GHz through 110 GHz with tuning bandwidths from narrowband (less than 1% fractional bandwidth) to wideband octave-spanning coverage. Output power, tuning sensitivity (MHz/V), linearity, and pushing/pulling specifications are tailored to your system requirements.
Mechanically Tuned Oscillators
For applications where a simple, reliable, fixed-frequency signal source is all that is required, mechanically tuned Gunn diode oscillators provide a cost-effective solution. These waveguide-mounted sources use a micrometer-driven tuning mechanism to set the output frequency, which is then locked in place for stable operation. No external PLL, power supply regulation, or digital control is needed.
Mechanically tuned oscillators are commonly used as bench-top LO sources for mixer testing, as signal sources in radar trainers and simulators, and as reference oscillators in laboratory setups where frequency agility is not required. We manufacture these sources across all standard waveguide bands from WR-28 (26.5 GHz) through WR-05 (220 GHz), with output power levels from +5 dBm to +18 dBm depending on the operating frequency.
Frequently Asked Questions
A phase locked oscillator (PLO) is a signal source that locks its output frequency to a stable reference using a phase locked loop (PLL). In frequency converter systems, the PLO serves as the local oscillator that drives the mixer stage. Because the PLO is locked to a crystal or OCXO reference, it delivers extremely low phase noise and high frequency stability, which directly determines the spectral purity and sideband performance of the converted signal. PLOs are preferred over free-running oscillators in SATCOM and radar systems where phase noise budgets are tight.
A voltage controlled oscillator (VCO) is a single-frequency tunable source whose output frequency changes proportionally to an applied tuning voltage. A synthesizer is a complete frequency generation system that typically contains a VCO inside a phase locked loop, along with reference oscillators, frequency dividers, and control logic. The synthesizer can be programmed to output precise frequencies with crystal-referenced accuracy, while a standalone VCO requires external circuitry to achieve the same precision. Synthesizers offer better phase noise, frequency accuracy, and programmability at the cost of higher complexity and switching speed.
Yes. All RF Essentials local oscillator and synthesizer products are designed and manufactured to your exact specifications. You define the center frequency, tuning range, output power, phase noise requirements, and mechanical interface, and our engineering team builds the source to match. Custom waveguide bands from WR-28 through WR-05, coaxial outputs, and integrated frequency multiplier chains are all available. Lead times vary by complexity but typical custom PLO and synthesizer builds ship in 8 to 12 weeks.