WR28 and WR90 Horn Waveguide Antennas

Horn waveguide antennas, such as WR28 and WR90, are essential components in high-frequency communication and radar systems. This article explores their working principles, unique features, and diverse applications.

A waveguide antenna utilizes a hollow metal tube, or waveguide, to transmit and receive electromagnetic waves. The waveguide acts as a physical structure, guiding and confining radio frequency (RF) signals within its interior and preventing electromagnetic wave radiation outside. Waveguide antennas are commonly used in microwave and millimeter-wave frequency bands, where traditional wire antennas can become impractical due to size and inefficiency.

These antennas are often found in radar systems, satellite communication, microwave point-to-point communication links, and other applications requiring high-frequency signals.

Different types of waveguide antennas exist, including rectangular, circular, and elliptical waveguides, each tailored for specific applications and frequency ranges.

The general specifications of waveguide antennas include:

• Frequency Range: The range over which the antenna operates satisfactorily according to its design specifications.
• Gain: Represents the antenna’s ability to focus beam radiation in a specific direction. Choose a gain that covers the desired area.
• Polarization: The polarization of the antenna, e.g., linear, circular. Match it with system requirements.
• Beamwidth: Indicates the angular coverage of the radiation pattern. Consider both horizontal and vertical beamwidth specifications.
• Directivity: Indicates the ability to concentrate energy in a specific direction. Higher directivity is desirable.
• VSWR (Voltage Standing Wave Ratio): A parameter used to assess the efficiency of power transfer between the antenna and the transmission line. Lower VSWR is desired, indicating reduced signal reflections and better matching.
• Power Handling Capacity: Determines the maximum power the antenna can handle without performance degradation.
• Impedance: Match the antenna impedance with the transmission line impedance to minimize signal reflections.
• Interface: Can be coaxial or waveguide.
• Size and Form Factor: Consider the physical size and form factor to ensure the antenna fits within the available space and meets installation requirements.
• Environmental Considerations: Evaluate the antenna’s ability to withstand environmental conditions such as temperature, humidity, and exposure to the elements.
• Materials and Construction: Assess the materials used in the construction of the antenna for durability and performance characteristics.

Types of Waveguide Antennas

• Rectangular Waveguide Antenna: Consists of a rectangular metal tube. Commonly used in microwave and millimeter-wave (mmWave) applications.
• Circular Waveguide Antenna: Features a circular cross-section, suitable for circular polarization and often used in satellite communication.
• Elliptical Waveguide Antenna: Has an elliptical cross-section, combining features of both rectangular and circular waveguides.
• Double-Ridged Waveguide Antenna: Features two ridges along the length of the waveguide. Employs broadband design for wide frequency coverage.
• Horn Antenna: Combines a waveguide with a flared, horn-shaped opening. Provides high directivity and is often used for radar and microwave communication. Categorized into Sectoral Horn and Pyramidal Horn Antenna types.
• Log-Periodic Dipole Array (LPDA) Waveguide Antenna: Consists of a series of dipole elements on a boom. Offers broadband characteristics and is used for frequency-independent antennas.
• Dielectric-Loaded Waveguide Antenna: Utilizes a dielectric material inside the waveguide to modify its properties. Used for achieving specific radiation patterns and impedance matching.
• Ridge Waveguide Antenna: Similar to a rectangular waveguide but with a raised ridge along the center. Enhances bandwidth and reduces cutoff frequency.

WR90 Horn Antenna

The WR90 standard refers to a specific size of rectangular waveguide commonly used in microwave engineering. The WR90 horn antenna typically operates in the frequency range of approximately 8.2 to 12.4 GHz and supports a gain in the range of 10 to 15 dBi. Beamwidths of around 30 to 60 degrees can be achieved, depending on the design.

The WR90 waveguide has a rectangular flange with specific dimensions. The horn antenna will have a corresponding flange to ensure proper mechanical and electrical connection. As per the waveguide dimension table, WR-90 horn supports an ‘A’ dimension of 0.400 inch and a ‘B’ dimension of 0.900 inch.

WR28 Horn Antenna

The WR28 horn typically operates in the frequency range of approximately 26.5 to 40 GHz and is often used in high-frequency applications such as point-to-point microwave links, radar systems, and millimeter-wave (mmWave) research.

WR-28 supports an ‘A’ dimension of 0.1400 inch and a ‘B’ dimension of 0.280 inch, with typical gains ranging from 15 to 25 dBi or more.

Popular vendors and manufacturers of waveguide antennas include RF-Lambda, PASTERNACK, Antenna Products Corporation, Radio Waves, QuinStar Technology, Inc., and Cobham Antenna Systems. Check their respective websites for other specifications of WR90 and WR28 horn antennas, such as polarization, VSWR, directivity, and aperture size.

Conclusion

WR28 and WR90 horn waveguide antennas are notable for their efficiency and versatility in microwave applications. Understanding their specifications aids in selecting the appropriate antenna for specific requirements.