A broadband planar image reject mixer

A 6-18 GHz Image Reject Mixer (IRM) is presented that is smaller and less expensive than the present suspended stripline technology products. The cost was reduced by designing novel building blocks that could all coexist on a single microstrip substrate. The novel components are quadrature couplers at IF and RF frequencies and a microstrip balun. Design methodology is presented along with measurements. Finally, the whole IRM is put together and characterized state-of-the-art performance is achieved and presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>