Antenna Performance Parameters
Interactive beamwidth and gain calculator for aperture antennas from 10 to 200 GHz. Supports parabolic, Cassegrain, and lens antenna geometries.
Antenna Type Selection Guide
• Lens Antennas are suited for small apertures (3″ to 12″ D) and provide moderate gain. They work well at millimeter-wave frequencies where compact size is essential.
• Cassegrain Antennas use a dual-reflector design for mid-to-large apertures. They offer high gain with a compact feed structure, commonly used in satellite and radar systems.
• Parabolic Antennas are the standard for large-aperture, high-gain applications. Surface tolerance becomes a limiting factor at higher frequencies.
How to Specify Millimeter Wave Antennas
Selecting the correct millimeter wave antenna for a radar or communications system is one of the most critical decisions in specifying a millimeter wave system. A properly selected and designed antenna yields measurable improvements in system capability, operational performance, and long-term reliability.
RF Essentials specializes in advanced antenna design covering the frequency spectrum from 12 through 220 GHz. With over 20 years of engineering experience, our team has developed techniques that yield superior performance and reliability. Our antennas are currently operating in defense installations, satellite ground stations, autonomous radar platforms, and scientific research systems around the world.
This guide covers a representative group of millimeter wave antennas and feeds currently available from RF Essentials. Our design capability extends well beyond what is shown here. We routinely engineer custom antenna systems, feeds, and complete antenna assemblies to meet specific operational requirements. Contact our engineering team with your specifications for a technical consultation.
Antenna Selection Process
Determine Operating Frequency and Bandwidth
The primary information required in antenna selection is the operating frequency and the required frequency bandwidth. Use the frequency slider in the calculator above to set your center frequency. The frequency determines your wavelength, which directly drives both gain and beamwidth for a given aperture size.
Select the Effective Antenna Diameter
The next parameter to determine is the effective antenna diameter. Standard diameters (3, 6, 9, 12, 18, 24, 36, 48, 72, and 120 inches) are available as production configurations. Sizes between standard diameters are available but may require nonrecurring engineering and additional lead time. When possible, select a standard diameter to minimize cost and delivery.
Read Beamwidth and Gain from the Charts
With frequency and diameter set, the beamwidth and gain are determined from the selection charts above. Alternatively, if your system requires a specific gain or beamwidth, you can work backwards: find the target value on the chart and trace it to the required diameter at your operating frequency. The charts relate beamwidth, gain, and effective antenna diameter for any given frequency. When one value and the frequency are known, the remaining two values can be derived directly.
Select the Antenna Type
Refer to the Antenna Type Selection Guide in the calculator above to identify the appropriate antenna configuration (lens, Cassegrain, or parabolic) for your diameter and frequency combination. Each type has distinct performance characteristics. Lens antennas are suited for compact apertures at millimeter-wave frequencies. Cassegrain designs offer high gain with compact feed geometry. Parabolic dishes provide maximum gain for large apertures but require tight surface tolerances at higher frequencies.
Address Mechanical and Environmental Considerations
Beyond electrical performance, mechanical factors such as wind loading, thermal expansion, radome requirements, mounting interfaces, and environmental sealing must be addressed. These considerations are best resolved during a direct technical consultation with the RF Essentials engineering team. Our engineers routinely design antennas for harsh environments including maritime, airborne, and space applications.
Important Note on Surface Tolerance
At millimeter-wave frequencies, antenna surface accuracy becomes a critical factor. The general rule is that surface deviations should be less than λ/16 (one-sixteenth of a wavelength). At 100 GHz, for example, the wavelength is approximately 0.118 inches, meaning surface accuracy must be held to within 0.007 inches (~0.18mm). RF Essentials manufactures antenna reflectors with surface tolerances exceeding this requirement through precision CNC machining and proprietary finishing processes.