The SKY16603-632LF from Skyworks uses two diodes in an anti-parallel configuration.
Radio receivers must often detect the low-level signals that carry modulated information while avoiding susceptibility to high-lever interference. The SKY16603-632LF from Skyworks consists of two PIN limiter diodes and DC blocking capacitors to protect sensitive receivers.
The diodes are arranged in an anti-parallel configuration. As Skyworks explains in its PIN Limiter Diode Design Guide:
During the positive or negative cycle of the incoming RF signal, one diode rectifies the incoming RF and produces a current proportionate to the incident RF power. One PIN diode, which is connected in an anti-parallel configuration to the other diode, provides a return path for the current and behaves like a current controlled resistor.
At power levels below the diode detection threshold, the unbiased PIN diode’s equivalent junction resistance is considerably higher than the transmission line characteristic impedance. Therefore, most of the incident power will pass through one limiter with almost no attenuation. Depending on the polarity, if the incoming RF signal is above the diode’s threshold, the rectification of RF produces a current that lowers the PIN diode equivalent resistance. At very low resistance values, most of the incident power is reflected back to the source and only a small fraction is dissipated in the PIN diode.
The SKY16603-632LF operates at frequencies from 600 MHz to 6 GHz, which covers the 5G sub-6 GHz frequency range. It has a typical insertion loss of 0.3 dB (0.5 dB max) and return loss of 22 dB, both specs at 2.6 GHz. It comes in a 2-pin, 2.3 mm² DFN package.