Second generation of surface-mount (SMT II) isolators and circulators, with frequency ranging from 800 MHz to 3.8 GHz. The SMT II devices are designed for low IMD application, PCB application, with very compact package and soldering reflowing durability. Minimum isolation is 20 dB, maximum insertion loss 0.35 dB, -75 dBc IMD with custom design available upon request.