共查询到20条相似文献,搜索用时 15 毫秒
1.
Shing Horng Lee Christina F. Jou Chien Ping Lee Cheng Chi Hu 《International Journal of Infrared and Millimeter Waves》1997,18(10):2001-2017
A simple varactor tuned X-band Gunn diode VCO antenna array which is strongly coupled has been demonstrated. These arrays
have the advantages of simple biasing circuit, no resistors required to eliminate multimode problem and suitable for monolithic
integration circuit. Preliminary results show a maximum tuning range of 47MHz for 1×1 array and 170MHz for 2×2 array. In order
to solve power combining heating problem, we move the backside metal forward and it becomes a microstrip form. The measured
frequency and radiation patterns of these grid arrays agree very well with theoretical calculations. 相似文献
2.
Xiaowei Zhu Yiyuan Chen Wei Hong 《International Journal of Infrared and Millimeter Waves》1996,17(3):527-533
The configuration and performance of a Q-band injection-locked Gunn oscillator are presented whose outport is connected with a phase-locked reference source by a circulator. The output power of the oscillator is more than 60mW at 46.1GHz. The single-sideband phase noise (SSB) is less than-71.7dBc/Hz offset 10KHz from the carrier, and the spectrum of clutter signal is less than -40dB. 相似文献
3.
R. S. Chen Q. T. Zhang K. N. Yung 《International Journal of Infrared and Millimeter Waves》1996,17(11):1947-1956
In this paper, the averaging method is used to analyse the performance of second subharmonically injection locked Gunn oscillator. Some useful expressions such as the locking range, output response, output impedance of nonlinear device in fundamental and subharmonic frequency are obtained. a W — band subharmonically locked Gunn oscillator is developed and experimental result demonstrates the validity of this analysis. 相似文献
4.
Cheng-tian Xue Qiao-min Wang Rong-lin Ding 《International Journal of Infrared and Millimeter Waves》1997,18(12):2307-2313
It is described that the design, configuration and the performance of a novel millimeter wave Gunn oscillator stabilized by
external cavity and temperature compensation in this paper. The frequency stability is 3.6 × 10−6 at 52 GHz over the teperature range from −10 to 50 °C. An output power of more than 100mW has been obtained in the frequency
range from 51.5 to 52.8 GHz.
This research work was supported by National Natural science Foundation and Electronic Industry Ministry of P. R. China. 相似文献
5.
Ch. Durga Prasad S. S. Sarin Deepak Singh 《International Journal of Infrared and Millimeter Waves》1996,17(2):393-402
A 35 GHz dielectric resonator oscillator(DRO) using GaAs Gunn diode in microstrip configuration has been designed and developed. The oscillator, with an integral waveguide-to-microstrip transition, delivered an output greater than 18 dBm. Phase noise of the oscillator is found to be better than –80 dBc/Hz at 100 KHz away from the carrier. A frequency drift of about ±25 MHz has been observed over the temperature range from –10 °C to 50 °C. 相似文献
6.
S. S. Sarin S. Ramakrishnan 《International Journal of Infrared and Millimeter Waves》1996,17(2):375-384
Pulsed Gunn oscillator at 94 GHz has been developed using GaAs CW Gunn diode, by choosing a proper operating point and resonant circuit. Peak power output of 25 mw at 94 GHz with a pulse width of 2 microseconds and duty factor of 2% is achieved. Bias circuit oscillations are suppressed by rising the operating voltage alongwith other circuit considerations. 相似文献
7.
M. Curow A. Abou-Elnour K. Schünemann 《International Journal of Infrared and Millimeter Waves》1996,17(2):305-316
A GaAs second harmonic Gunn oscillator for D-band applications is proposed. The doping structure of the active device has been optimized using Monte-Carlo and hydrodynamic models. The load impedance characteristic of a resonant mounting structure in a WR06 waveguide has been consistently taken into account. At sufficiently low load resistances and reactances, output powers of the order of 20–50 mW should be obtainable around 140 GHz under realistic thermal conditions. 相似文献
8.
Y. M. Tao J. Nin G. Y. Delisle 《International Journal of Infrared and Millimeter Waves》1995,16(10):1769-1772
GaAs Gunn diodes were fabricated for pulse source application at 8 mm wave band and operated with pulsewidths of 0.05 to 2.0 microseconds and duty cycles of 0.001 to 0.01. Peak pulse output power levels of 0.8–1.2W are achieved and the maximum available power is 1.6W with the highest efficiency of 6.5 percent. A simple and compact pulsed power combiner is also given in this paper. 相似文献
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We predict that the flow of unpolarized current in electron-doped GaAs and InP at room temperature is unstable at high electric fields to the dynamic formation of spin-polarized current pulses. Spin-polarized current is spontaneously generated because the conductivity of a spin-polarized electron gas differs from that of an unpolarized electron gas, even in the absence of spin-orbit interaction. Magnetic fields are not required for the generation of these spin-polarized current pulses, although they can help align the polarization of sequential pulses along the same axis. 相似文献
14.
基于满足目前高效复杂的调制技术对功率放大器线性化度越来越高的需求的目的,采用模拟预失真技术设计了一种线性化器,用来改善Ka频段氮化镓(GaN)固态功放的非线性化失真。通过改进传统的并联式二极管预失真电路,采用开环技术,将两个肖特基二极管并联。改变二极管的偏置状态,得到不同的改善程度的预失真信号。结合使用专用电磁仿真软件ADS2013做电路仿真,通过参数扫描得到二极管偏置状态的初始值,为实物调试提供理论基础。通过对已加工的实物测试,结果表明:增益幅度补偿达到6.4dB,相位补偿达到28°。 相似文献
15.
Nick Lioutas Nick Fourikis 《International Journal of Infrared and Millimeter Waves》1991,12(7):845-857
Many receivers operating at millimetre wavelengths utilise a frequency downconverter as their first stage. A rugged, low-conversion loss and simplified cross-bar mixer operating at the atmospheric window centered at 33 GHz was designed, developed and tested as a forerunner to mixers operating at atmospheric windows centred at higher frequencies. The cross-bar mixer exhibits a conversion loss of less than 5 dB over a bandwidth of 2 GHz. Design and optimisation procedures of the mixer are outlined. 相似文献
16.
Conclusion It was demonstrated that approaches towards oscillators with sufficient noise performance familiar up to frequencies of 100 GHz can be applied at 140 GHz with only minor modifications.Mostly due to the limitations imposed by the available InP Gunn diodes the power levels reached with second harmonic mode operation were less than at 94 GHz with GaAs devices. The two approaches employing IMPATT diodes deliver substantial output power at D-band. Which one is preferrable will be dependent on the application. 相似文献
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18.
N. N. Rosanov 《Optics and Spectroscopy》2012,112(6):898-901
Periodic excitation of an oscillator by an external signal close to an exponential one with a complex frequency at the main part of the period is analyzed. The characteristics of a stabilized excitation regime are determined, as are its features when approaching the complex resonance, when the complex frequency of an external signal at the main part of the period is compared with the complex eigenfrequency of the oscillator. A criterion of closeness to the complex resonance is suggested. Estimations of the allowed level of intensity, when nonlinear distortions of the oscillator response are insignificant, are presented. 相似文献
19.
为了满足现代通信设备多频带及集成化要求,基于耦合机理和谐振机理,在实心半波壁雷达罩和A 夹层雷达罩等效平板基底上设计了一种由容性表面(内嵌谐振单元)-感性表面-容性表面(内嵌谐振单元)-等效基底级联而成的Ku/Ka波段双通带频率选择表面结构. 根据FSS的物理结构建立了等效电路模型,分析了滤波机理,利用全波分析软件计算了两种FSS雷达罩的传输特性. 该结构基于容性表面与感性表面的耦合作用在Ku波段形成具有微型化特性的第一通带,基于两个容性表面内嵌的方环单元谐振在Ka波段形成第二通带,两通带透过率分别为89%,94.7%(实心半波壁FSS雷达罩)、88.2%/93.7%(A夹层FSS雷达罩),在0°–45°扫描范围内,两通带传输特性稳定. 在半波壁雷达罩的等效平板上制作了Ku/Ka双通带实验样件,利用自由空间法测试其传输特性,在制作误差允许的范围内,测试结果与仿真结果基本一致. 为研究通带间隔较宽的多频FSS 提供了理论和实验依据.
关键词:
雷达罩
频率选择表面(FSS)
双通带 相似文献
20.
为解决传统分支线定向耦合器带宽较窄,且应用到线性化器等微波元件中时受谐波信号影响较大的问题,提出了一个宽带且带有谐波抑制功能的定向耦合器。该定向耦合器在双支节定向耦合器的基础上增加一个支节,可有效地提高定向耦合器的带宽,同时将其传输线支节替换为低通滤波结构,以实现对高次谐波抑制的作用。仿真结果表明,该定向耦合器的反射系数和隔离度均小于-15 dB,传输损耗小于3.8 dB,波动范围0.5 dB,相位差为90°且与双支节耦合器相比增加1 GHz带宽。满足耦合器的设计指标,可应用到微波元件中,提高微波元件的性能。 相似文献