Papers by Keyword: Millimeter-Wave

Abstract: This paper presents a novel structure of millimeter-wave amplitude equalization based on low temperature co-fired ceramic (LTCC) technology, which is implemented by substrate integrated waveguide (SIW) resonator, thin film resistor, microstrip-line and metallic via hole probe. It has advantages of compact, easy for integration, low cost, low loss, and mass-producible. The effects of each component for equalizer performance have been analyzed by simulation. In order to validate the new proposed topology, a millimeter-wave gain equalizer is developed and verified by full-wave simulation using 9-layers Ferro A6 substrates. The designed equalizer exhibits excellent performances.

Abstract: In this paper, a linearly polarized microstrip patch array antenna is analyzed based on the theory of cavity mode. Using the weighted parallel fed method, a 64 element linear polarization microstrip array antenna with a 35.5GHz center frequency is designed. Then we use the simulation software optimize the simulation model of the antenna. The simulation result shows that this antenna has a gain of 22dB, and low sidelobes.

Abstract: The millimeter-wave transceiver front-end as a subsystem of high-frequency component is an important part of the radar, navigation, electronic warfare and communication systems. The millimeter receiver front-end developed herein, using the second harmonic mixer, reduces the frequency of the local oscillator. Using the bottom surface outlet ladder microstrip - waveguide structure, it strengthens the structure. Test results show that the developed front-end receiver has gain of 25dB and the transmit band is 35.5-36GHz.

Abstract: In recent years, with the development of millimeter-wave MMIC chip, millimeter wave technology has been widely used. The millimeter-wave transmitter front-end is designed in this paper. By using second harmonic mixers, we reduce the operating frequency of the oscillator. By using the side exit microstrip - waveguide structure, we strengthen the compact structure. Test results show that the transmitter front-end transmission power is 33dB and its transmission band is 35.5-36GHz.

Abstract: The letter reports the analysis of the reduced-size planar microstrip Wilkinson power divider which uses miniaturized microstrip line instead of conventional quarter wavelength transmission line. The full design formulae of the miniaturized Wilkinson power divider with arbitrary power ratio is first proposed.3dB one-stage and two-stage miniaturized Wilkinson power divider are designed according to the formulae. The ADS EM simulation results of the one-stage miniaturized Wilkinson power divider when the smaller electrical angle is 45 degrees show its reflection coefficient<-20dB,isolation>20dB and the transmission loss<0.4dB in the bandwidth of 28.9-34.9GHz,for the two-stage reduced-size Wilkinson power divider its reflection coefficient <-20dB,isolation>20dB and the transmission loss<0.4dB in the bandwidth of 26-37.5GHz.This kind of miniaturized Wilkinson power divider has a very compact size as well as good match and isolation.

Abstract: This article describes a method of IF modulation used in millimeter-wave transmitter, the method is AD9857 combined with FPGA, choose the EP1C6 as a FPGA chip, and use this FPGA chip complete the base-band digital signal processing, and implement the control to the AD9857. AD9857 is a kind of the orthogonal frequency converter based on DDS technology, complete the functions of base-band digital signal interpolation filter, orthogonal modulation, and D/A conversion in the digital domain and complete QDPSK modulation signal output of 70MHz IF carrier. This method can eliminate phase and gain imbalances and distortion which caused by analog modulation, also can simplify the system structure, reduce cost and improve the performance and reliability of the system.

Abstract: Exfoliated graphite with different expanding volume (EV) was prepared by two-step intercalation, in which the mixture of nitric acid and phosphoric acid, and that of nitric acid and acetic acid were employed as intercalating agent step by step, and potassium permanganate was used as oxidant. Its microstructure was analyzed by scanning electron microscope, and its millimeter-wave attenuation performance was measured by a static method. The results show that the exfoliated graphite forms more microcellular structures and its layers become thinner with the increasing of EV, the interlayers are fully opened and there are more tiny graphite flakes with size distribution between several microns and several ten microns. The millimeter-wave attenuation performance enhances with the increasing of EV, and the 3mm wave attenuation value rises from 5.7dB to 8.68dB When EV increases from 233ml/g to 450ml/g, which is mainly attributed to the full expansion of exfoliated graphite to form larger scattering cross section and the absorption of more tiny graphite flakes with size distribution between several microns and several ten microns.

Abstract: A novel multipoint-to-multipoint bandwidth allocation algorithm named MP2MP-DBA based on 60GHz millimeter-wave communication is proposed for home network. Simulation results show that the MP2MP-DBA achieves better throughput and delay than static bandwidth allocation algorithm.

Abstract: Lifetimes of RF MEMS (Micro-electro-mechanical systems) capacitive switches are hindered by dielectric charging effects. A novel test structure for experimental verification of millimeter-wave MEMS switch dielectric accumulation charge is presented. The structure, which is designed using EM simulation software CST Microwave Studio and HFSS, consists of Coplanar Waveguide (CPW), a 2-way power divider and two symmetric capacitive MEMS switches. The input signal is equally divided into two output signals in the 2-way power divider due to symmetry, and the isolation between two output ports the power divider of is less than -48dB at 35GHz. The designed millimeter-wave capacitive MEMS shunt switch has 0.076dB insertion and -55dB isolation at 35GHz. The two symmetric capacitive MEMS switches in this structure can provide a strong comparability for different switch dielectric accumulation charge situations.

Abstract: A novel millimeter-wave transition from microstrip to rectangular waveguide is introduced in this paper. The theory for this design is explained. The strip conductor on microstrip, which is introduced from the center of a rectangular waveguide broad-wall to its E-plane, is shaped into a triangular loop in the waveguide terminated by a short circuit. A back to back transition operating at Ka band was simulated and fabricated. The experimental results showed the insertion loss of a back to back transition is less than 2.2dB with its return loss greater than 9.1dB from 26.5 GHz to 35.5 GHz.