A C-Ku-Band RF Module Transmitter Including an RF Signal Generator for a Flexible Phased-Array System

This paper presents a new concept of an active phased array antenna (APAA) system with RF modules, including an RF signal generator. The proposed APAA realizes multi-frequency and multi-modulation beam forming simultaneously by generating an RF signal independently in each module and sharing them among the antenna arrays. This configuration is effective in a distributed array radar system because the interconnect equipments of modules can be simplified by not transmitting an RF signal on the cables. Moreover, the proposed APAA can compensate the performance variation between output signals of RF modules. These features contribute a flexible and precise APAA operation. Key features of the proposed APAA are verified by measurements. A transmitter block of the RF module with three silicon-germanium integrated circuits is fabricated to validate the proposed functions and performances. The fabricated RF module generates the various modulated signals of 1 Gs/s and operates in C-Ku-bands. It is achieved that the measurement accuracy of timing error, phase error, and amplitude error of RF output signals are 56 ps . rms, 0.6 degrees . rms, and 0.6 dB . rms, respectively.