Microtek introduces a range of in-house manufactured absorptive harmonic waveguide filters, which, when used with high-power microwave amplifiers, avoid the potential damage that reflective filters can cause. The AMQ-HARM series of filters is designed to absorb signals with harmonic frequencies higher than the specified pass band, rather than reflecting them back to the amplifier. Manufactured from light-weight aluminium, these compact filters are available in waveguide sizes from WR137 to WR62 for applications in the frequency range 5.8 to 18.4 GHz, with harmonic frequencies up to 40 GHz. They feature a sealed, pressure-tight design that makes them particularly suitable for use in high-power transmitters such as radar TWTAs (traveling-wave tube amplifiers), where pulsed powers are commonly in the tens of kilowatts range. In addition, the AMQ-HARM filters are likely to be of interest to any EMC test houses equipped with high-power broadband microwave amplifiers to reduce unwanted higher frequency signals.