Microstrip to CPW transitions for package applications

Microstrip (MS) transmission lines are widely used at RF, microwave and millimeter-wave (mmWave) frequencies in monolithic integrated-circuits (ICs), printed circuit boards, and planar antennas. At mmWave frequencies, RF transceivers typically use coplanar waveguide (CPW) pad structures. As a result, MS-to-CPW transitions are necessary to connect the antennas to the RF transceivers. Furthermore, to accurately evaluate these antennas at mmWave frequencies, MS-to-CPW transitions are required since CPW (i.e., ground-signal-ground (GSG)) probe-based measurement systems are used. Probe-based measurement systems avoid the use of connectors on antennas; therefore, de-embedding is not required. In fact, connectors are not used in many mmWave antenna designs. © 2010 IEEE.