This work presents an integrated direct-conversion in-phase receiver front-end for carrier frequencies around 180 GHz with an RF bandwidth above 80 GHz. The circuit consists of a double-balanced active mixer core with baseband output buffer, local oscillator (LO) driver and low noise amplifier. Passive baluns are used for the single-ended to differential conversion. The design is optimized for ultra-wideband communication systems with good linearity to support higher order modulation schemes. The saturated conversion gain is 14 dB with a double-sideband noise figure of 12 dB. The optimal LO power is -10 dBm and the RF input referred 1-dB compression point occurs at -15 dBm. The LO driver allows a usable carrier range of 160 GHz to 200 GHz. The total power consumption is 100 mW and the final chip occupies an area of 0.75 mm2. It is fabricated in a 130 nm SiGe BiCMOS process with a maximum oscillation frequency of 450 GHz. Compared to the state-of-the-art this circuit offers one of the highest RF bandwidth of any receiver with fixed carrier, making it a viable option for wireless transmission systems achieving data rates beyond 100Gbit/s.