Showing papers by "Mithilesh Kumar published in 2019"

Implementation of Metamaterial Loading to Miniaturized UWB Dipole Antenna for WLAN and WiMAX Applications with Tunability Characteristics

Abstract: This paper presents a double-printed circular slot inscribed, hexagonal shape miniaturized dipole antenna represents the ultra-wideband (UWB) characteristics with the implementation of linearly tap...

Development and performance analysis of conformal UWB wearable antenna under various bending radii

Abstract: Antennas for off-body wearable applications needs to be flexible and its electrical characteristics should be stable in different body postures, different bending or stretching environments. Therefore, the designed antenna should be such that, even if the antenna is bent frequently, it should operate properly. In this paper, a conformal UWB antenna is reported which has been optimized to be conformal to any body shape and size. The proposed antenna has been designed on RT Duroid substrate with dielectric constant of 2.2 and loss tangent 0.0009. The thickness of the material is 0.127 mm. Due to low thickness; it can easily be bent and mounted on curved surfaces. The size of the antenna is 35 × 31 mm2. To accomplish the design process, two different bending radii have been considered to bend the proposed antenna. The two bending radii of 25 mm and 50 mm have been chosen; one corresponding to the arm of a healthy child of around 5 years age and another corresponding to a healthy person of age about 35 years with medium built. The simulated radiation efficiency and total antenna efficiency are more than 60% for the bending at 25 mm and 50 mm radii in the UWB frequency range from 3.1 GHz to 10.6 GHz. The gain of the proposed antenna for both the bending radii is changing from 1.4 dB to 5.3 dB. The return loss of the proposed antenna is obtained for 25 mm and 50 mm bending radii of curvatures and it is below 10 dB in UWB range. A prototype of proposed antenna has been fabricated and tested on Rohde & Schwarz 40 GHz VNA. Measured results are in close agreement with simulation results.

Frequency Reconfigurable UWB Antenna Design for Wireless Applications

Abstract: A frequency band reconfigurable antenna is designed and experimentally analyzed. Proposed design achieve UWB (3.1–10.6 GHz), two dual band and two narrow band switching states by implementation of PIN diodes inside the slotted ground. Antenna covers the various wireless standards WLAN, WiMAX, WiFi and UWB with return loss S11 < −10 dB. Proposed antenna is also operating at 9.2 GHz to include the airborne radar applications. Simulated and experimental results are compared and found to be in good agreement.

A High Gain Low Noise Figure Double Balanced Down Conversion Mixer for Band 1 of WiMedia System

Abstract: Objective: To propose an improved double balanced down conversion mixer for band 1 of WiMedia system at RF frequency of 3.432 GHz and IF frequency of 264 MHz. Method/Analysis: The proposed mixer is based on the Gilbert cell architecture. It uses switch bias technique to improve the noise figure and resistive current injection technique to improve the conversion gain and linearity. A resonating inductor is used to cancel out the effects of parasitic capacitances. Moreover, T type impedance matching, LC impedance matching and output buffer are used at RF trans conductance stage, LO switching stage and load stage respectively for matching purpose. Mixer is simulated in 0.18 μm CMOS technology using keysight Advanced Design System (ADS) software. Findings: Simulation results show that mixer achieves maximum conversion gain of 8.057 dB, third order Input Intercept Point (IIP3) of -10.88 dBm, Double Sideband (DSB) noise figure of 3.515 dB and S11 of -22.926 dB at 1.8 V dc supply voltage. Novelty/Improvement: A high gain, low noise figure double balanced down conversion mixer with low value of input reflection coefficient and suitable linearity is proposed for band 1 of Wimedia system. Keywords: Current Injection Technique, Double Balanced, Down Conversion Mixer, L and T Type Matching Networks, Switch Bias Technique, Wimedia System

Low Voltage Low Noise Figure Down-Conversion Mixer for Band 1 of WiMedia System

Abstract: A Low voltage and low noise figure double-balanced down-conversion mixer is proposed and implemented using ADS software in a 0.18µm CMOS process technology, at 1V DC supply voltage. The proposed mixer use DTMOS (Dynamic Threshold Voltage MOSFET) configuration at RF and LO stages for low voltage operation. LC ladder circuit is used for matching at RF port. Current injection technique is used to enhance the conversion gain. The proposed mixer is designed for a RF frequency of 3.432 GHz with an IF frequency of 264 MHz. Simulation of mixer shows maximum conversion gain of 9.212 dB, P1dB of −17.2 dBm, IIP3 of −4.828 dBm, S 11 of −29.404 dB and a SSB noise figure of 6.720 dB.

Measurement Analysis of Ultra-Wide-Band and Ultra-Wide-Band-MIMO Antennas: Review and Analysis

Abstract: This chapter mainly focused on the recent trends in the antenna design techniques for next-generation wireless communication systems. Ultra-wideband antenna and multi-input-multi-output antennas are very useful to achieve higher data rates. An antenna is a transducer that changes guided electromagnetic energy in a transmission line to radiated electromagnetic energy in free space. Antennas may also be observed as an impedance transformer, coupling among an input or line impedance, and the impedance of free space. The looming widespread commercial deployment of ultra-wideband (UWB) systems has flashed new interest in the subject of ultra-wideband antennas. The power levels approved by the FCC mean that every dB counts in a UWB system as much as or possibly even more so than in a standard narrowband system. Thus, in effect, UWB antenna is a precarious part of an overall UWB system design. Basic principles for ultra-wide-band (UWB) antenna design and radiation are presented and discussed in this chapter.