This paper presents a Ku-band SiGe BiCMOS phased array receive chip capable of forming four-simultaneous beams from two antenna inputs. The design is based on the all-RF architecture with 4-bit active phase shifters and 4-bit variable gain amplifiers in each channel. The four-beam chip results in a gain of 4-6 dB per channel at 13-15 GHz, a noise figure of 10-11 dB, a worst case input P1 dB of -14.3 dBm per channel (input third-order intercept point of -7 dBm), and an rms phase and gain error of < 12?? and 1.5 dB, respectively. A gain control of 17 dB is also achieved with a phase change of < 5??. The four-beam chip was tested using two input signals and results in a gain of 9-11 dB at 13-15 GHz. The on-chip isolation between the channels has been fully characterized and is > 40 dB at 13-15 GHz. The chips can operate over an instantaneous bandwidth of > 1 GHz at any frequency from 13 to 15 GHz, and the four beams can be at the same frequency if required. With all digital control circuitry and electrostatic discharge protection for all I/O pads, the chip occupies an area of 2.4 ?? 4.3 mm2 and consumes 520 mA at 3.5-V supply voltage. To our knowledge, this is the first demonstration of an all-RF phased array silicon chip capable of producing four-simultaneous beams from two different antennas or four-simultaneous beams of different polarizations from a dual polarization antenna. The application areas are in satellite communications and defense systems.