Quadrifilar Helix Antenna for Satellite and GPS Communication

The Quadrifilar Helix Antenna is a circularly polarized antenna intended for applications where a wide beamwidth and reliable signal reception are important. Smart Electronics Communications (SEC Antenna) is involved in the design and manufacture of antennas for HF, VHF, UHF, microwave and S-band voice and data communication. Its product range includes circular polarized models for satellite communication and GPS tracking.

SEC Antenna lists SQFH137G5 at 137 MHz with 5 MHz bandwidth and 2–5 dBi gain, and SQFH400G5 at 380–450 MHz with 8 MHz bandwidth and 2–5 dBi gain. The company also says its antennas are designed according to band and application requirements.

Quadrifilar Helix Antenna – What Is It?

A Quadrifilar Helix Antenna is made of four helical radiating elements configured to generate a circularly polarized radiation pattern. Its large beamwidth makes it well suited for communication systems that need wide coverage and do not require accurate antenna pointing.

SEC Antenna offers circular polarized designs in both right-hand circular polarization (RHCP) and left-hand circular polarization (LHCP). The antenna structure uses copper radiating material, and fiberglass radome options are available for environmental protection. SEC Antenna also lists features such as low VSWR and high performance.

How Does a QFH Antenna Work?

The desired radiation pattern and circular polarization are obtained through the four helical elements of a Quadrifilar Helix Antenna. A matching section supports low-VSWR wide-band operation. SEC Antenna states that four copper wires or pipes are circularly wrapped with uniform spacing to ensure a smooth radiation pattern and wide beamwidth.

The large beamwidth can be useful for satellite communication and GPS navigation applications because the antenna can receive signals without the need for precise directional alignment. SEC Antenna states that its models are designed to operate in the UHF satellite band and can be supplied for specific research and communication requirements.

Quadrifilar Helix Antenna Applications

A Quadrifilar Helix Antenna can be used for various communication applications depending on its frequency and system requirements. SEC Antenna has identified the following applications:

• Amateur Radio Satellite Communication

   

• GPS Navigation & Tracking

   

• Satellite Communications (Analog)

   

• Satellite Communications (Digital)

   

• UHF Satellite Band Communication

   

• Communication Systems for Research

Its broad-beam feature makes it suitable for systems where satellite signals may come from changing positions. Its circular polarization can be selected based on the polarization requirements of the communication system.

Things to Look For

When choosing a Quadrifilar Helix Antenna, take into account frequency, bandwidth, gain, polarization, VSWR, construction and mounting requirements.

Bandwidth and Frequency

The antenna should operate in the operating band of the communication equipment. SEC Antenna has models for 137 MHz and the 380–450 MHz range, each with different bandwidth specifications.

Gain and Polarization

Gain and polarization should match the communication system. Antenna performance is affected by these parameters. SEC Antenna provides RHCP and LHCP options on its circular polarized models.

Building & Protection

The radiating element is copper and the radome is fiberglass for SEC Antenna. Antennas are lightweight, mast/pole mountable and come with stainless-steel mounting hardware. 

SEC Antenna Quadrifilar Helix Antenna

SEC Antenna provides circular polarized antenna solutions in application-specific configurations. The antennas can be provided with custom connectors, custom paint colors and custom finishes as per customer specifications. The company states that the products are designed and manufactured according to the gain requirements of the operating band and application.

Summary

The Quadrifilar Helix Antenna is intended for communication systems needing circular polarization and a broad beamwidth. The model should be selected according to the frequency, bandwidth, gain, polarization, VSWR, construction and installation conditions.

SEC Antenna offers QFH Antennas for satellite, GPS and other communication applications, with configurations designed around frequency and application requirements.