This paper presented the effects of Defected Waveguide Structure (DWS) toward wideband monopole antennas. Ultra-wideband (UWB) technology was introduced to support high data rate and maximum bandwidth utilization. Monopole antenna received great attention owing to its appealing features of planar in the structure and is easy to manufacture in miniaturized sizes. Yet, poor gain and directivity are always the drawbacks of the miniaturized antennas. It was found that there was no research work done on the monopole antenna design with DWS. Two wideband monopole antennas with a microstrip feed line and coplanar waveguide (CPW) feed line were proposed. Two waveguides with full copper and square DWS were designed at all the inner walls. Monopole antennas were then integrated in the waveguides. The antenna parameters studied were return loss, efficiency, gain, directivity and radiation pattern to investigate the effects of DWS toward monopole antennas. Both monopole antennas achieved wide bandwidth from 2.5 GHz to 11 GHz and higher efficiency of more than −2 dB. Monopole antennas with waveguide presented a narrower bandwidth from 6 GHz to 11 GHz but a significant directivity improvement of 5 dBi at a lower frequency of 4.5 GHz. Monopole antenna with square DWS demonstrated high directivity and gain in a wide bandwidth of 8.5 GHz. Higher gain was improved around 4 dB at the frequency of 4.5 GHz, and high efficiency of more than −2 dB was achieved. The DWS design served as a guide for future communication system based on the smart technology system.

/pdf/effects-of-defected-waveguide-structure-toward-wideband-mpeget4sbz.pdf

Effects of Defected Waveguide Structure Toward Wideband Monopole Antennas

Multipoint displacement measurement based on low intracavity-loss FLRD method

AbstractA waveguide bandpass filter (WBPF) based on the Chebyshev response that operates in the E-band system for downlink channel [71 GHz–76 GHz] at 73.5 GHz resonant frequency has been designed and simulated. The new design of the WBPF used complementary split-ring resonators (CSRRs) that both rings are located transversely on the metallic sheet. Lumped circuit of the filter has been implemented and discussed as well. The circuit of the prospective bandpass filter has been designed and demonstrated via electromagnetic full-wave simulator CST. By selecting proper physical dimensions of CSRRs, a shortened physical length, a flat and lossless passband, and better return loss rather than the traditional waveguide filter. Subsequently, the proposed waveguide BPF and the traditional WBPF which coupled with inductive H-plane resonators have been compared at the same resonant frequency 73.5 GHz. The new waveguide bandpass filter shortened the physical length of WBPF by \(37.5\%\) and boosted the return loss up to \(6.7\%\).KeywordsMicrowave filterMetamaterialsWaveguideResonatorsE-band 

Design of Chebyshev Bandpass Waveguide Filter for E-Band Based on CSRR Metamaterial

This paper present the design of E-band E-plane bandpass waveguide filter with the E-plane inserted metal strip. And the waveguide filter is analyzed and optimized by filter structure character. In simulation, the E band waveguide electromagnetic simulation software according to the waveguide filter is operated from 72.2GHz to 73.8GHz with the maximum insertion loss of 0.41dB. And the relative bandwidth of the waveguide filter is about 2%. At last, contrast about the experiment results and the simulation data is analyzed.

A E-band E-plane type waveguide bandpass filter

• A displacement sensor using FSI combined with active FCRD technology is proposed. • A Bi-EDFA is utilized to increase the number of round trips for achieving high resolution. • A sensitivity of 0.05 km −1 ·nm −1 with stability of 1.3 % was achieved. • Using the proposed method, the displacement sensor with resolution of 0.3 nm was achieved. A displacement sensor of sub-nanometer resolution using space-domain active fiber cavity ring-down (FCRD) technology was developed. In our scheme, by combining active FCRD with frequency-shifted interferometry technology, a sensitivity of 0.05 km −1 ·nm −1 was achieved and the stability was improved mostly because this scheme is free from the power fluctuation of a light source, benefited to the use of low-noise Bi-EDFA and the differential detection method to reduce the direct current noise. Besides the first sensitivity amplification process is involved in this technique due to the multiple times rounds of interaction between the light pulse and the sensor head in the fiber cavity, the secondary sensitivity amplification process is realized by using a Bi-EDFA to compensate the inherent cavity loss of fiber cavity, which results in a significantly improvement in resolution. The experimental results show that our proposed displacement sensor can achieve a resolution of up to 0.3 nm with stability of 1.3 %. 

Displacement measurement of sub-nanometer resolution using space-domain active fiber cavity ring-down technology

The purpose of this study is to develop a magnetic particle imaging (MPI) technique to directly measure time-varied cerebral superparamagnetic iron oxide nanoparticle (SPIO) concentration in rhesus macaques. A hand-held MPI detector was developed to monitor MPI signal changes at the third harmonics of the drive frequency in resting-state nonhuman primates. Phantom experiments were first performed to determine the sensitivity limits of the detector as a function of distance from the detector and SPIO concentration. The measured sensitivity profile was then used to reveal the most sensitive region of the detector. MPI detection was continuously performed to monitor MPI signal changes after two bolus injections of SPIOs in the rhesus macaque. We successfully developed a hand-held MPI to detect cerebral SPIO concentration changes in a living nonhuman primate. The detection limit of the MPI detector is about 125 ng iron. We reported on the in vivo measurement of cerebral SPIO concentration changes in rhesus macaque using a hand-held MPI detector. In vivo experiments showed the feasibility of the detector to sensitively measure MPI signals in a nonhuman primate brain.

https://ieeexplore.ieee.org/ielx7/5165412/6832516/10141661.pdf

In Vivo Measurement of Cerebral SPIO Concentration in Nonhuman Primate Using Magnetic Particle Imaging Detector

The paper reports on the design and performance of a high power backward wave oscillator (BWO), working at Ku-band frequencies. The rectangular waveguide grating structure is used as its slow wave structure. The backward wave oscillator is driven by a sheet beam with cross sectional area of 30mm×1mm which is generated by a thin cathode. For a beam voltage 185kV, and beam current 3.2kA, the output power is 2.5MW at 14.3GHz.

http://or.nsfc.gov.cn/bitstream/00001903-5/515866/1/9913552215.pdf

A Ku-band high power backward wave oscillator

High-throughput satellite mainly provides Internet service, which has higher date transmitted rate dozens of time than the traditional communication satellites. The maximum utilization of satellite power and satellite capabilities is of great significance for improving the performance of high-throughput satellite systems. The ability to deliver power flexibly between beams throughout is key to HTS payload[1],[2].MPA(Multi-port Amplifier)is research hot spot in recent years on HTS satellite, which is a way to realize flexible payload. In This paper, a design method of Ku-band MPA based on traditional LCTWTA is introduced.

Jie He

Papers

A E-band E-plane type waveguide bandpass filter

Displacement measurement of sub-nanometer resolution using space-domain active fiber cavity ring-down technology

In Vivo Measurement of Cerebral SPIO Concentration in Nonhuman Primate Using Magnetic Particle Imaging Detector

A Ku-band high power backward wave oscillator

A design method of a Ku-band Multi-Port Amplifier