After the introduction and justification of several more or less well known and complicated conversion topologies based on series resonance, this chapter will focus on the design of the non-reversible series resonant converter. Following this, a brief description will be given concerning a collection of DC/DC and DC/AC converters developed under various industrial contracts by the Laboratoire d’Electrotechnique et d’Electronique Industrielle (L.E.E.L), Toulouse, France.

Design and Applications

In this paper, a new multi-band PIFA antenna covering four frequency bands (GSM, Wifi/Bluetooth, 4G LTE and WIMAX) is presented The proposed method in this work consists of two main phases The first step consists in determining the electrical and radiation characteristics of the proposed antenna using HFSS simulator The second step, the effects of this antenna on the human body is examined and the specific spatial peak absorption rate (SAR) in the human head caused by the use of mobile phone is reduced applying the adaptation technique For this reason, experiments were carried out based on LC resonator placed between the generator and the load and put in series with the short circuit After optimizing the values of L and C, theoretical and experimental results were compared and discussed to obtain a good compromise between some constraints: (1) simulation and measurement results are in good agreement on the return loss (RL) (= S11), (2) high bandwidth, (3) high radiation efficiency and (4) limited specific absorption rate

New Design of Multi-Band PIFA Antenna with Reduced SAR for Mobile and Wireless Applications

LNA is a vital component in radio frequency communication systems. Various applications of low noise amplifier are reviewed in this paper. The design considerations for low noise amplifier are different for different applications. Comparative study of different applications of LNA has been done and reviewed in this paper.

A review of various applications of low noise amplifier

In a radio frequency (RF) transceiver, low noise amplifier (LNA) plays a critical role in determining the receiver performance. This paper elucidates the design of an LNA for optimizing its gain, noise figure and stability factor with different transistor configurations in the frequency range of 5-6 GHz. Design-optimization of LNA has been performed with standard transistor (BJT and MOSFET) files in circuit simulation software. For comparison we have considered the following configurations of LNA: (i) a single stage npn BJT LNA, (ii) npn BJT and NMOS cascode LNA, and (iii) npn BJT and CMOS cascode LNA. Simulation results show that compared to other configurations npn BJT-NMOS cascode LNA depicts the highest gain of 20.42 dB and the lowest noise figure of 0.25. On the other hand, npn BJT-CMOS cascode LNA demonstrates the highest stability factor of 1.07 followed by npn BJT LNA and npn BJT-NMOS cascode LNA configurations respectively. Further improvement in the LNA performance metrics is feasible by parametric optimization of transistor parameters and passive elements in the matching network.

Performance Analysis of Radio Frequency (RF) Low Noise Amplifier (LNA) with various Transistor Configurations

This paper presents the design and simulation of High gain Source degenerated Cascode LNA for Wi-max and W-CDMA applications at 3.5GHz. The design uses an enhanced cascade topology to attain improved forward gain and noise figure. Th is design includes lumped elements like inductor, capacitor and resistors to design input and output matching networks. The targeted narrow-band gain, impedance matching and noise figure are achieved at the 3.5GHz. Circuit has been designed Using standard UMC 0.18μm CMOS technology and simulated in the Cadence Spectre RF tool. Targeted narrowband gain, noise figure, are 25dB and 2dB respectively. The designed circuit exhibits narrow-band gain of 27.18 dB and noise figure of 1.7 dB with Input and output return loss of -17.57 dB and -29.21 dB respectively. Circuit operates from the supply voltage of 1.8V and draws a current of 6.39mA.

A high-gain Source degenerative Cascode LNA for Wi-MAX and W-CDMA applications at 3.5GHz

This paper presents the design of a high gain low noise amplifier operating in a bandwidth of 5014 GHz for wireless applications High gain of 1617dB is achieved at a frequency of 4 GHz The Low noise amplifier is an electronic amplifier used to amplify possibly very weak signals Its mostly placed at the front-end of a radio receiver circuit so that the effect of noise from subsequent stages of the receiver chain is reduced by the gain of the LNA The transistor used here for the design of LNA is GaAs FET N76000 The high gain low noise amplifier is designed by using AWR microwave office version

Design of a high gain low noise amplifier for wireless applications

This paper presents a multiband planar inverted F antenna for mobile handset applications. The novel idea of F-shaped slot technique is introduced into the conventional rectangular patch antenna for higher GSM frequency. The proposed antenna features rectangular patch antenna for GSM (880-960MHz) band and F shaped slot antenna for DCS (1710-1880MHz) and GSM (1710-1880MHz) bands. The feed for the multiband antenna is Z-shaped feed and coaxial feed. The impedance bandwidth of proposed antenna is 34.1MHz (0.917 GHz-0.9511 GHz) at lower band and 60MHz (1.77GHz-l.83GHz) at upper operating band. The directivity is 2.69dB and 5.69dB at 0.93GHz and 1.8GHz. The radiation pattern is nearly omnidirectional in both the planes. The parametric studies were carried out by High Frequency Structure simulator (HFSS).

Design of tri band antenna for mobile handset applications

This paper presents a multiband planar inverted F antenna for mobile handset applications. The novel idea of meandering technique is introduced into the conventional rectangular patch antenna for higher GSM frequency. The proposed antenna features rectangular patch antenna for GSM (880-960MHz) band and meandering slot for DCS (1710-1880MHz) and GSM (1710-1880MHz) bands. The impedance bandwidth of proposed antenna is 41MHz (0.882GHz-0.923GHz) at lower band and 110MHz (1.66GHz-1.77GHz) at upper operating band. The radiation pattern is nearly omnidirectional in both the planes. The parametric studies were carried out by High Frequency Structure simulator (HFSS).

Sandeep Kumar Veeravalli

Papers

Design of a high gain low noise amplifier for wireless applications

Design of tri band antenna for mobile handset applications

Design of multi band antenna for mobile handset