Ka Band Delay-line Components Based On LTCC Technology

With the enhancement of strategic position and higher operating frequency, wider bandwidth requirements, radar systems are developing towards miniaturization and multi-function. As one of the most important parts of phased array radar systems, the further development of delay line components can contribute to realize the instantaneous technology in transceiver modules.The delay line is an electrical components used to delay a signal for a period of time, which also requires a flat Amplitude-Frequency characteristics, low attenuation and small dispersion, good impedance matching and a certain phase shift between its input signal and its output signal. Recently, LTCC technology develops rapidly because of its excellent performance, such as low loss, high reliability and high integration. Compared with traditional one, the delay line using LTCC technology is more suitable for modern radar systems for its merits of miniaturization and high integration. This thesis focuses on the research of delay-line module based on LTCC technology.Firstly, the passive LTCC delay-line module is studied, focusing on the research of microstrip, stripline, coplanar-line and inter-layer via transition based on LTCC technology through theoretical analysis and 3-D modeling.In addition, wire bonding technology for Ka-band is researched in this thesis. According to the simulation results, increasing the number of bonding wire can significantly improve the transmission performance of the module and port impedance match.On the basis of the above work, a delay line module working at Ka-band is designed using LTCC technology. The module consists of six-way delay line units, which can provide 1 ?,2 ?,4 ?,8 ?,16 ?,32 ? time delay respectively. Each delay line unit is composed of delay line and equal loss transmission line. The delay line is fabricated on Ferro A6-M material. Bending the stripline in the substrate can realize module miniaturization and reduce the dispersion characteristics. Equal loss transmission line is fabricated on ceramic substrate. A gain equalizer is adopted in the equal loss transmission line design to increase the loss under the condition of not affect the VSWR. All delay line units are connected in sequence, which can provide a time delay from 1 ? to 63 ? with a step of 1 ? through MMIC SPDT switches in the driving control circuit. The size of the delay-line module is 84 × 47 × 15 mm3.According to the measurement, the module has a small dispersion effect and good VSWR. At the same time, it significantly improved the disadvantages of conventional delay lines such as the large bulk, lossy and small adjustable range.This thesis has an important reference value for microwave transmission type delay-line module. Meanwhile, it can lay a solid foundation for the miniaturization of radar systems.