Waveguide Attenuator Up to 5000 Watts

I. Core Principles

Waveguide attenuators operate based on the loss and conversion of electromagnetic energy, primarily achieving attenuation through the following mechanisms:

1. Absorption Principle: An absorber (such as a graphite- or nickel-chromium alloy-coated dielectric sheet) is placed parallel to the electric field direction within a waveguide (usually a rectangular waveguide). Electromagnetic waves generate a conduction current on the surface of the absorber, converting electromagnetic energy into heat energy through Joule heating, thus reducing signal power.

2. Cutoff Principle: Utilizing the cutoff characteristics of waveguides (waveguides attenuate signals below the cutoff frequency exponentially), a circular waveguide operating in the cutoff state is used. By adjusting the position of the output coupling coil (changing the transmission distance), linear adjustment of the attenuation is achieved (e.g., waveguide cutoff attenuators).

3. Polarization Principle: Composed of three waveguide segments (rectangular-to-circular transition waveguides at both ends, and a rotatable circular waveguide in the middle). By rotating the absorber within the middle circular waveguide, the absorption ratio of the electric field component is changed, achieving a linear relationship between attenuation and rotation angle (commonly used for high-precision adjustable attenuation).

II. Key Parameters

1. Attenuation: The power reduction in decibels (dB) after signal transmission, typically ranging from 0 to 60 dB (some high-precision models can reach 120 dB).

2. Operating Frequency: The compatible waveguide frequency band (e.g., 2.6~40 GHz, also used in the terahertz band).

3. VSWR: Reflects the impedance matching degree; high-quality products can achieve ≤1.15 (typical value ≤1.10).

4. Power Capacity: The maximum input power it can withstand (the waveguide structure enables it to carry high power at high frequencies).

III. Typical Applications

1. Signal Level Control: Inserting attenuators before amplifiers, power probes, and other equipment to prevent signal overload or equipment damage.

2. Testing and Measurement: Serving as an attenuation reference, improving system matching, reducing mismatch errors, and enhancing measurement accuracy.

3. System Isolation: Reducing signal crosstalk and mutual coupling between devices, improving the stability of multi-channel systems.

4. Impedance matching: Improves the load's VSWR, ensures the traveling wave state of the transmission line, and reduces signal reflection.

Waveguide attenuators, with their advantages of high frequency, low loss, and high power capacity, are irreplaceable fundamental components in microwave/millimeter-wave systems. Their performance directly affects the system's signal quality and reliability.