On-Chip InP Based Series Fed Patch Antenna Array with Via less GCPW to Microstrip Transition

Integrated, beam-steering transceivers are crucial for mobile E-band applications and beyond. On-chip series-fed antenna arrays provide an efficient solution for beam steering without requiring complex feeding control circuits. This paper presents an eight-element on-chip series-fed patch array with a grounded coplanar waveguide to microstrip (GCPW-to-MS) transition, designed without need of via holes. The antenna is implemented on a high-permittivity Indium Phosphide (InP) dielectric substrate, ensuring high performance. By incorporating a low-loss GCPW-to-MS transition, the proposed array achieves a wide bandwidth of 67 – 90 GHz, a peak realized gain of 8.5 dBi, and a radiation efficiency of 75% at 80 GHz. The via-free on -chip array design enhances manufacturability and integration, making it a strong candidate for compact, high-frequency transceiver applications in 6G.