UHF Antenna Types: From Folded Dipoles to High-Gain Yagis

UHF — typically the 300 MHz to 3 GHz range, though most UK PMR applications sit in the 400–470 MHz window — is home to a wide range of antenna types. TETRA, DMR, PMR, and a large proportion of IoT and critical infrastructure applications all operate in this band. Knowing which UHF antenna type is right for a given installation is one of the most practically useful decisions an RF specifier makes.

Omnidirectional Whip and Blade Antennas

The standard for mobile and portable UHF installations is the omnidirectional whip or blade antenna. These radiate equally in all horizontal directions, making them suitable for vehicles, handhelds and base stations that need to communicate with users approaching from any direction. Gain figures range from 0 dBd for a quarter-wave whip up to around 6 dBd for a collinear design. Higher-gain collinears achieve their gain by compressing the radiation pattern towards the horizon — useful for base stations on flat terrain, but potentially counterproductive in hilly or dense urban environments where signals arrive from above and below the horizontal.

Folded Dipole Antennas

The folded dipole is a robust, broadband design widely used in base station and repeater applications. Its nominal 0 dBd gain and omnidirectional pattern make it a reliable choice where predictability matters more than peak gain. The folded dipole's wider bandwidth compared to a simple half-wave dipole is a practical advantage where small frequency offsets between channels are involved.

UHF Yagi Antennas

For directional gain in the UHF band, a Yagi is the standard choice. Compared to VHF equivalents, UHF Yagis are physically compact — a 12-element UHF Yagi at 430 MHz is a significantly smaller structure than a 12-element VHF Yagi at 155 MHz. This makes UHF Yagis practical for mounting on vehicles, temporary structures and restricted rooftops. They are widely used as base station receive antennas, for point-to-point links, and as gain antennas for TETRA infrastructure where coverage must reach into a valley or be focused across specific terrain.

Panel and Sector Antennas

In infrastructure and in-building applications, UHF panel antennas provide directional gain in a compact, flat form factor. Available in single-polarisation and cross-polarisation designs, they deliver precise, controlled coverage for building-mounted applications, road corridors, car parks and campus sectors.

Choosing by Application

PMR base station on flat terrain: high-gain collinear omnidirectional. TETRA infrastructure with point-to-point links: Yagi or panel. Repeater site on a hilltop: omnidirectional dipole or low-gain collinear. Vehicle TETRA or DMR: whip or blade. In-building repeater distribution: panel antennas for directional feeds, omnidirectional low-gain for coverage distribution. IoT base stations: omnidirectional collinear.

Browse Renair's UHF antenna range at renair.co.uk/products.

Frequently Asked Questions

What is the difference between a whip and a blade antenna for UHF?

Both are omnidirectional. A whip is cylindrical and typically higher-gain; a blade is flat-profiled and more aerodynamic, making it the standard for vehicle installations. Blade antennas are also more resistant to mechanical damage in low-clearance environments.

Why does my UHF collinear perform worse in hilly terrain?

High-gain collinear antennas achieve gain by squeezing the radiation pattern towards the horizontal. In hilly terrain, where signals need to propagate at angles above and below the horizontal, this narrow vertical pattern creates coverage nulls. A lower-gain antenna with a wider vertical beamwidth often covers hilly terrain better.

Is a UHF Yagi suitable for TETRA?

Yes. UHF Yagis covering the 380–400 MHz TETRA band are used in repeater and infrastructure applications, particularly for directional links between base stations. Confirm the antenna's frequency range covers the TETRA sub-band in use and that VSWR across the operating channel range is within specification.