A Wideband Termination Based on Laser-Scribed Lossy Microstrip Line Structures

Laser-direct writing has become an alternative method to fabricate microwave devices. We present a laser-scribed wideband open-end termination that relies on conductor loss of the microstrip line structure to obtain effective absorption. The proposed design consists of a resistive film overlapped on a strip conductor, providing an enlarged sheet-resistance range (20 omega/similar to 1.2 k omega/) of the resistive film to reduce the fabrication difficulties. The resistive film is in tapered shape to enable small gradual changes in impedance, yielding minimized reflections (|S-11|). The prototype is demonstrated utilizing the laser-direct writing technique, with a measured |S-11| over -15 dB from 6 GHz to at least 30 GHz. The termination can also be used for attenuation over a -10 dB attenuation level (>8.5 GHz) with a low reflection level better than -15 dB (>2.0 GHz). This study can be employed for the applications where cheap wideband planar terminations are needed and promote fast, flexible, and low-cost prototyping or modification of the existing microwave circuits.

Automated summary

Laser-direct writing has been used to fabricate a wideband open-end termination for microwave devices, utilizing a resistive film overlapped on a strip conductor to reduce fabrication difficulties. The tapered shape of the resistive film enables small gradual changes in impedance, resulting in minimized reflections. The prototype demonstrates good performance with a measured |S-11| over -15 dB from 6 GHz to at least 30 GHz.