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We report the successful development of a broadband, high-linearity MMIC PA. This single PA is useful for multiple wireless systems including satellite mobile ground terminal, GPS transmitter, WiFi repeater, and WiMAX repeater applications. Using GaAs MESFET technology, we connect two 12 mm FET unit cells both RF and DC in series (HIFET) to achieve a total gate width of 24 mm. This way, the DC bias...
UHF radios are subject to out-of-band interferers. As a result, a co-site interference filter is often necessary. This paper presents a design method and test results of a bandpass filter subject to very wideband requirements (10 kHz - 20 GHz).
The hemispherical open resonator feeding by the rectangular waveguide was analyzed by using the modal analysis method. The open resonator was excited by the rectangular waveguide through a narrow slot, with a complete analysis of all the relevant modes in the waveguide and the open resonator, the coupling coefficients according to the difference width slots were derived among Ka waveband, further...
A simple and cost-effective experimental setup for measuring the transmission coefficient of whispering-gallery (WG) mode dielectric resonators up to the mm-wave band is presented. The proposed setup consists of a sweep generator, a spectrum analyzer and a PC with a General Purpose Interface Bus (GPIB). The major advantage of such arrangement lies in the ease of measurement without standard calibration...
The 1 Kilo-Watt Amplifier Pulsed amplifier has been designed and tested for driving a Klystron power amplifier. The amplifier consists of a Class A multistage, single ended pre-driver using commercially available MESFET devices and consists of bias sequencing and voltage regulation. The 30 dB gain Amplifier operates from a single supply. The pre-driver is followed by a 50 Watt GaN single stage amplifier...
A novel distributed oscillator (DO) is reported with cascade of inductive coplanar waveguide (CPW) coupled two common-source n-FETs, the novel gain-cell of DO. Two common-source n-FETs are connected with each other through a coplanar waveguide only, acting as an on-chip inductor. The design uses 3 stages of n-FETs cascade gain cell, with a bias of 1.4 V. This oscillator called OSC-1 operates at K-band...
The Linear Amplification with Nonlinear Components (LINC) power amplifier structure combiner implementation has an effect on the linearity and efficiency of the design. Understanding and using this tradeoff is helpful to radar and communication designers and can be used to assist in operating with optimum efficiency while meeting spectral mask requirements instituted by regulatory agencies. In this...
Many sensor network design problems are characterized by the need to optimize multiple objectives. However, existing techniques in sensor network design generally optimize only one objective while treating the others as constraints or convert the multi-objective optimization problem into a single objective optimization problem using weights associated with different objectives. The weighted sum approach...
Recent advances in MMIC GaAs PHEMT amplifiers have pushed intermodulation (IM) distortion performance beyond the traditional relationship between intercept point and compressed output power levels making them ideal candidates for use in broadband digital transmission using complex modulation such as OFDM and QAM. Single-ended and push-pull structures have improved IP3 and IP2 performance; however,...
This paper will describe methods developed to enhance the effective integration of complex systems. A variety of integration techniques will be described for coplanar waveguide based architectures used for in-plane and three-dimensional wafer scale packaging. Each approach offers low loss and low dispersion characteristics from DC to V-band and in special cases W-band.
This paper describes a novel technique to measure the input impedance of on-chip microstrip patch antenna in standard CMOS technology. By using the measured impedance of IMPATT diodes fabricated in the same standard CMOS technology and three lateral IMPATT diodes integrated with a microstrip patch antenna at one of the radiating edges, oscillation can be achieved and accurate measurement of the antenna...
A method for analyzing the overall noise performance of vital sign detectors is introduced. For demonstration purpose, the noise analysis on a quadrature direct-conversion vital sign detector is performed. The detector is divided into three sub-systems including RF Front-end amplifiers, mixer with LO, and baseband amplifiers. The noise characteristics of the sub-systems are studied individually and...
The purpose of this paper is to present recent results on the integration of SAW orthogonal frequency coded (OFC) wireless sensors into a unified sensor target at 915 MHz. Current proof of concept embodiments at 250 MHz and 915 MHz have been successful in demonstrating a functional sensor design and working interrogation system. However, previous work has done little to optimize the sensor platform...
The ever increasing global space activity is characterised by emerging space systems, operation and applications challenges. Hence, reliable RF and microwave receivers for in-orbit highly adaptive small satellites are needed to support reconfigurable multimedia/broadband applications in real-time with optimal performance. Though other parameters of the small satellite communication system may be critical,...
This paper describes the design, fabrication, and applications of a novel high resolution electric field probe. In essence, the probe consists of a novel miniaturized open-circuited co-axial transmission line that can respond to local normal electric fields with a spatial resolution of about 100 microns. A key aspect of the probe is the use of an active amplifier close to the probe tip. This amplifier...
A systematic, first-pass methodology for designing high efficiency power amplifier (PA) using only large signal CAD models is presented. Detailed analysis using the model reveals significant insights into PA operation as well as the required impedance environment for high efficiency mode of operation. In particular, waveform engineering and empirical loadpull are used to determine the optimal class...
The conventional Doherty amplifier requires the auxiliary device current to increase faster than the main as the input power increases. This has been accomplished by additional control circuitry, or uneven power drive, or periphery scaling. This paper presents a new Doherty design approach that accepts the insufficient auxiliary device current. It is shown that with this approach, comparable power...
This paper presents an experimental study, in which Time-Domain pulse technique is used to characterize the performances of an Ultra-Wide Band (UWB) antennas. Pulse with 4.0ns duration is generated, modulated and used to measure the far-field characteristics of printed antennas at 5.25GHz. The proposed method can be used for characterizing Ultra Wide Band antennas in the time domain, especially in...
Modeling GaN transistors is still a matter of research. The technology is still quite young and not yet fully mature. A second issue is the fact that GaN transistors are commonly used as packaged power devices. This paper discusses modeling results obtained for different GaN devices from a small HEMT to a 60-W packaged power transistor. It is shown that the performance state-of-the art GaN HEMTs are...
In this work we present the design and fabrication of a linear array of printed monopole antennas embedded within the wing structure of a small Unmanned Aerial Vehicle (UAV) and operating in the 2.4 GHz ISM band. Integration of antenna elements within UAV structures will reduce the weight and cost. Also, the use of embedded antenna arrays will increase the communication range and data throughput....
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