Ultra-compact lumped element cross-over

A novel ultra-compact wide-band microwave cross-over using lumped components is presented for the first time. The proposed cross-over is composed by inductors and capacitors, and the explicit design equations are derived based on the even-odd mode method. The size of the proposed cross-over is 1 × 1 cm², and the bandwidth is 20-30%. Full-wave electromagnetic simulations are performed and an experimental prototype is fabricated to demonstrate the novel design concept. The measurement results match well with the theoretical and numerical results.