A 65 - 100 GHz impedance transforming hybrid coupler for a V- /W-Band AlGaN/GaN MMIC
This paper demonstrates the feasibility of impedance transforming lumped-distributed branchline couplers (LDBC) at millimeter-wave frequencies. Simulation and measurement results of a W-band 50 (omega) to 18 (omega) transforming coupler are compared and show a good agreement. The LDBC has a relative bandwidth of 42% (65 GHz- 100 GHz) and an insertion loss of about 1 dB at 80 GHz. A balanced power amplifier is presented employing the designed hybrid coupler to demonstrate the overall performance.