To meet the requirements of millimeter wave circuits for high-current and high cutoff-frequency devices, a compact 4-finger InGaAs/InP single heterostructure bipolar transistor(HBT) was designed and fabricated successfully by using planarization technology. The results show that the width of the emitter fingers is as small as 1μm, the high Kirk current of 4-finger HBT reaches 110mA, and the current gain cutoff frequency is as high as 176GHz. The device is promising on the applications in the medium-power circuits operating at millimeter-wave range.