Ka-band Rd Send And Receive High-frequency Front-end

Transceiver front-end is an important part of the modern microwave and millimeter wave system. Miniaturization, high precision and high reliability are the main developing directions for the precise guiding system. Based on millimeter wave precise guiding theory, the high-frequency Ka-band transceiver front-end with five channels has been achieved by employing the hybrid integrated circuit technology. The front-end has five transmitting channels, five receiving channels, two testing channels and a radio self-testing channel. Whenever at room temperature, high-low temperature or the vibration conditions it could complete the functions including switching between sweeping frequency and spot-frequency, switching among channels, switching beams, transmission power management and self-test functionIn this paper, key problems relevant to the high-frequency Ka-band transceiver with five channels have been researched. The main research work focuses on the following aspects.First of all, based on substrate integrated waveguide (SIW) technology and directional coupler theory, a new type of three-way with zero-phase difference power divider / combiner is designed. This power splitter has the advantages of low insertion loss, high isolation, small size, tiny three-way power and phase imbalance. If it is made of the half-mode substrate integrated waveguide, the size could be reduced by half. Meanwhile, the X-band and Ka-band Wilkinson power dividers used in the transceiver have also been designed.Secondly, based on half-mode substrate integrated waveguide (HMSIW) technology and K / J impedance transforming theory, a new type of narrow-band filter in X-band has been designed. The filter has very narrow bandwidth, small insertion loss, good selectivity, high suppression beyond the pass band, and excellent agreement with the simulation and test data. It is suitable for small, high-performance filter design. In this paper, at the same time, a C-band band pass filter employing half-wave open-loop resonator, a Ka-band E-metal band pass filter using waveguide, a Ka-band parallel band-pass filter by using coupled line and a band stop filter have been also designed. All of these four kinds of good performance filters have been used in the transceiver front-end.Thirdly, according to specification goals and programs of the system, the decoding circuits, door circuits and other digital logic circuits which are used to control 18 switches in the 13 channels of the transceiver have been designed.Finally, control circuits in the transceiver front-end including FPGA, DDS swept source, PLL frequency point source, local oscillator chains and the transceiver components are distributed rationally to ensure the overall system's miniaturization and reliability.Test results show that output power of five transmits channels of the high-frequency transceiver front-end is about(28±1)dBm. 6dB attenuation (18dB at most) in every step can be reached. Transmit spurious are less than -50 dBc. Isolation among transmit channels is greater than 45 dB. Gain and noise figure of the five receive channels is (30±0.5)dB and better than 5 dB respectively. Isolation between the receive channel ports is greater than 45 dB. All design goals of the transceiver front-end are achieved.