We describe active millimeter-wave monolithic integrated circuits (MMICs) dedicated to directional links serving as bit-transparent wireless bridges in fiber-optical systems. The design and performance of amplifiers, frequency converters and frequency multipliers are discussed. The 10 m transmission of a 25 Gbit/s on-off-keying signal based on multi-functional MMICs operating at an RF center frequency of 220 GHz is shown. Finally, a chip set for a broadband wireless link in the RF frequency range from 200 to 280 GHz is presented.