基于宽边耦合带状线结构,该文设计了一种基于低温共烧陶瓷(LTCC)技术的高隔离低插损3 dB 90°电桥.该电桥使用螺旋耦合线有效地减小了器件尺寸,同时以对称式结构建模更便于后期的优化调整.在宽边螺旋耦合带状线垂直方向引入一个伸入式可调隔离电容,极大地提高了该电桥的隔离度,使其可达27 dB,且插入损耗≤0.2 dB,较之传统的定向耦合器结构,其在提升性能的同时大幅减小了器件尺寸.对耦合线直角拐弯处的电场强度进行分析与优化,采用45°斜切的方式使拐角处的电场强度与直线处大致相等.对上接地金属板进行环形镂空处理,这将改善带内的幅度平衡度.该文设计的3 dB 90°电桥通带为0.96～1.53 GHz,插入损耗≤0.2 dB,幅度平衡度≤±0.7 dB,相位平衡度为90°±1°,隔离度≥27 dB,其具有良好的应用市场.

基于低温共烧陶瓷(Low temperature co-fired ceramic,LTCC)技术设计了一款C波段超宽带、高抑制的带通滤波器,并通过LTCC技术对滤波器进行加工制作,满足了小体积、高性能、密集封装的应用需求.滤波器整体上采用了低通滤波器与高通滤波器串联的结构实现超宽通带,并引入传输零点来增加带外抑制,采用垂直叉指电容和双层螺旋电感来减少滤波器体积.最终实现的滤波器通带的中心频率为5.3 GHz,带宽为3 GHz,通带内插损小于0.8 dB,在DC～3 GHz处抑制达到了 36 dB,在8～14 GHz处抑制达到了 35 dB,通带回波损耗为12 dB.滤波器体积为:1.8 mm×1.0 mm×0.7 mm.

该文设计了基于低温共烧陶瓷(LTCC)技术的双波段高抑制、低损耗的双工器.该双工器由低通滤波器和带通滤波器组成,且在低、高频段的阻带抑制方面运用了传输零点理论,在实现双工器低损耗的同时,也实现了在多波段的高抑制,提升了双工器的性能.该双工器在低频段(0.68～0.95 GHz)及高频段(1.43～2.40 GHz)时插损均小于1.2 dB,但在1.43～2.40 GHz时双工器抑制大于20 dB,0.68～0.95 GHz时双工器抑制大于15 dB.在4.9～5.9 GHz时双工器抑制大于13 dB,具有良好的市场应用前景.

设计了有一种基于低温共烧陶瓷(LTCC)工艺的小型化高性能带通滤波器.该滤波器采用集总参数形式,通过加入多级LC谐振,在滤波器近端增加多个传输零点来增加其在近端的抑制.经过电磁仿真优化,实际加工滤波器的测试结果与软件仿真相吻合.滤波器通带为5500 MHz~5900 MHz,其插入损耗小于2.5 dB,在5500 MHz抑制大于15 dB.该滤波器已经在一些WLAN模块中得到使用.

For sharing existing communication resource to meet the coverage of new communication system,a bandpass and bandstop combiner based on coaxial cavity is presented.Analyzing and simulating the circuit model of combiner,simulating and optimizing the structure of combiner with HFSS,finally a WLAN three-port combiner based on coaxial cavity is manufactured,making WLAN system merge into existing 2G/3G communication system successfully,and the measured results have good agreement with simulated results.Moreover,the combiner has many advantages such compact size,and easy-tuning,which are useful in practical applications.

In this paper, a novel three-port combiner based on coaxial cavity is presented, which consists of a band-pass filter with a transmission zero and a ultra-wideband band-stop filter, and the combiner is different to the conventional combiner based on microstrip or stripline. The design and simulated results show that the novel combiner has a good performance, which are insert loss more than -0.5dB and return loss less than -20dB between the GSM/DCS/TD band (800-2170MHz) and WLAN band (2400-2500MHz), the isolation in both bands less than -85dB, respectively. In addition, the performances of the novel combiner are demonstrated experimentally, the measured results have good agreement with simulated results.

In this paper,a novel two-port bandstop filter based on coaxial cavity is proposed,which is different to the conventional bandstop filters based on microstrip or stripline.The design and simulated results show that the novel bandstop filter has a good performance,which are stopband rejection less than -80dB from 1920MHz to 1980MHz, return loss less than -20dB and insert loss more than -2 dB in two widebands from 1700MHz to 1910MHz and 1990MHz to 2200MHz,respectively. Moreover,the measured results have good agreement with simulated results.

With the rapid development of communication system, the requirement for the accuracy of passive inter-modulation values is increasing. The interaction between contact points causes the deviation of PIM of the device under test; the problem that was neglected becomes increasingly important. Aiming at this problem, this paper simplifies the interaction among contact points as a model of multi-connectors connected (contacted) each other. Based on the mathematical model of connected multi-connectors, we have established an error analysis model of contact points in passive inter-modulation test system. We use two inter-modulation analyzers working in 900 MHz band and measure eight pieces of DUTs. Each time when one DIN7/16 connector is connected 20 tests are carried out until the number of connectors reaches to seven. Test results show that due to the impact of the connector contacts, the inter-modulation test result of DUTs is far beyond the norminal value. Using the proposed model of error correction, the PIM of DUTs can be controlled within the required accuracy range of the passive components.

This paper focused on a dual-band combiners which effectively improves the power capacity,using parallel band-stop filters with rectangular coaxial structure.Compared with mainstream domestic and foreign 300W devices,the 500W combiner effectively improved the power capacity.The theoretical analysis of rectangular transmission lines was presented as well as the design of rectangular coaxial dual-band combiner with full-wave simulation software.The simulation results agreed well with experimental results after physical processing and measurement.The combiner has significant benefits on high-power and low loss.

A dual-frequency coaxial cavity combiner was designed and implemented by the parallel band-pass filters composed of coaxial with square cavity.Using a synthetical optimization method(a method of circuit and full wave optimization simulation),we could obtain the coupling coefficient between resonators and the input-output structure parameters.Measured results show that is a good agreement with simulation after physical processing and measurement.