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This paper demonstrates the design and simulation of input matching circuit for BLF578XR power transistor working at center frequency of 225 MHZ with bandwidth of more than 50 MHZ. Based on the calculated Q-factor and when using the transistor in push pull mode, the input matching circuit is designed in two stages, the first stage is a balun to match 50 ohm to 12.5 ohm and the other stage is to match...
Negative impedance converters (NIC) are widely used for impedance matching of electrically-small antennas (ESA). For example, impedance of electrically-small monopole antenna contains high capacitive component and negative capacitance can be used to compensate this. Such negative capacitance can be realized with the use of NIC circuit based on wideband and low noise operational amplifier. Most of...
The technique of multiple points feeding in order to achieve improved bandwidth performance is here exploited and used to feed a supershape structured radiator. The achieved operating bandwidth, is an important advancement compared to the performance of the usual, single fed and regularly shaped patch antennas. The proposed antenna operates from 2.5 to 3.9 GHz with linear polarization and its behavior...
A novel compact microwave absorber with a 10dB absorption level to operate in the wireless communication bands in 1.8 GHz – 2.1 GHz frequency range is investigated. A robust equivalent circuit (EC) model using a new non-resonance constituent parameter extraction technique based on the interpretation of the E- and H-field distribution is discussed. The EC model and the proposed topology is developed...
DC microgrid is becoming popular due to high efficiency, reliability and easy integration of renewable sources. Droop controller based distributed technique is used in dc microgrid for proportional power sharing among sources. However, due to interconnecting cable impedance, trade-off exists between power sharing accuracy and voltage regulation. Centralized controller achieves these objectives using...
This paper describes the effect of wire with small circular ground plane size (radius < λ/20) for normal mode helical antenna at which resonance condition is achieved without using any external impedance matching network. A comparative study of variation in performance of helical antenna with respect to variation in thickness of wire and ground plane size at 1.8 GHz is carried out using simulation...
This article presents the first experimental results of an integrating Radio-Frequency DAC (RF-DAC) we called the Riemann Pump. This DAC is part of a complete waveform generator architecture based on the quantization of the signal variations and the conversion of the as-obtained digital signal into the analog domain. This technique provides an improvement of the coding efficiency with respect to conventional...
This paper presents a novel compensation scheme for two-stage CMOS operational amplifiers. The proposed solution is based on voltage-buffer compensation, but uses a gain stage in the feedback compensation path. An additional degree of freedom is introduced and a wider separation of the first two poles is achieved. A compensation procedure is proposed to benefit from these advantages. The proposed...
This paper presents an UWB monopole antenna with rectangular slots on the patch and defected ground surface. The proposed antenna has a dimension of 25mm∗30mm∗1.6mm fabricated on FR4 dielectric substrate material with dielectric constant (εr) 4.4. The microstrip feed is incorporated to monopole with rectangular slots on both the ground plane and patch which produce the extra resonance frequencies...
In this paper, a novel dielectric resonator antenna (DRA) design for ultrawideband (UWB) applications is proposed. A hybrid T-shaped DRA is excited by a conformal trapezoidal shaped patch feeding mechanism. It is observed that by introduction of air gap and use of two different DRA materials, Q-factor can be reduced and in turn UWB can be achieved. A rigorous parametric study of the proposed antenna...
This paper presents a novel inductorless transimpedance amplifier (TIA) design using Global Foundaries 0.18-µm CMOS technology suitable for high speed optical communication. A modified-RGC preamplifier stage (M-RGC) is used to lower input impedance through cascode and parallel PMOS transistor techniques for wideband operation. The amplifier stage used common source amplifiers to increase the gain...
In this article a microstrip antenna is reported for wideband wireless communication application. The main radiator of this design is printed in the front side of a piece of FR4 dielectric substrate while a finite ground plane is etched on the rear side. To achieve wide operating band, the ground plane is reduced to partial one and defected by inserting slots on its upper edge. It is found that this...
Cost efficiency and supply reliability are of major interest for power grids and networks. Therefore, we introduce a novel approach for power line diagnostics using channel measurements of power line communication devices. This approach does not require the test subject to be taken out of service. Periodic channel measurements provide insight into possible quality degradations of the cable as well...
Aiming to achieve Ultra Wideband (UWB) performance, this paper presents an improvement of the square-shaped phase shifter design, which covers from 2.8 GHz to 10.6 GHz by implementing step impedances in order to improve the impedance matching of the phase shifter, whilst leads to better scattering parameter results. The phase shifter design is formed by using multilayer technique where 3 layers of...
Impedance analyzers are often used for characterization of many electrochemical devices, such as photovoltaic cells, fuel cells and batteries, that are commonly utilized in renewable energy applications. Depending upon specifications of these devices, they are quite expenseive and their use in many low-cost applications is limited. This study demonstrates a practical impedance analyzer application...
A coplanar waveguide (CPW) fed circularly polarized monopole antenna is presented. The monopole antenna is placed inside a hexagonal shaped slot which is acting as a ground plane. A pair of L-shaped stubs are placed diagonally inside the slot. In order to enhance the impedance bandwidth a spiral discontinuity is created in the grounded ring, near to the edge of the L-stub. The measured result shows...
In circularly polarized radiation, the rotational orientations of the transmitter and the receiver antennas are unimportant in relation to the received signal strength. In this paper, a center square slot cut elliptical patch microstrip antenna to realize a tunable circular polarization in 1000 MHz frequency band is proposed. It yields axial ratio bandwidth of nearly 1.2% over tunable range. A rectangular...
A highly linear trans-impedance amplifier TIA is proposed to meet stringent linearity requirements of SAW-less frequency-division duplexing (FDD) LTE receivers with 20MHz channel bandwidth. In the proposed solution the operational amplifier is compensated exploiting the passive feedback network in order to achieve wide bandwidth and low power dissipation. The prototype in 28nm CMOS achieves 14dB of...
This paper presents an ultra-broadband low-noise amplifier (LNA) operating from 16 to 43 GHz in a 0.25 pm SiGe:C BiCMOS technology. Across this band, the LNA achieves simultaneous low-noise performance (2.5–4.0 dB) and power matching (S11 < −10 dB) using dual-LC tank matching. The measured minimal noise figure is 2.5 dB at 26 GHz with an average value of 3.25 (±0.75) dB from 16 to 44 GHz. The best...
This paper presents a design for 1–6 GHz low noise amplifier (LNA) based on cascade GaN HEMTs with LC ladder input matching and stabilizing output impedance. The designed LNA is simulated using Advanced Design Software (ADS) based on a commercial packaged transistor from Cree Inc. The LNA shows a maximum noise figure of 2.95 dB in the 1–6 GHz range with a gain of 14 dB. It also has a maximum S 11...
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