LTE Applications Research Articles

DESIGN AND ANALYSIS OF DOUBLE U SLOT LOADED DUAL FREQUENCY MICROSTRIP ANTENNA

The objective of the work is to design a dual frequency microstrip antenna for small frequency ratio applications. The proposed geometry comprised of suspended truncated circular microstrip antenna, with double U slot etched on the radiating element. The design parameters are radius of circular patch, width and length of slot, height of air gap. The proposed design of the antenna has enough freedom to control the dual design frequencies/frequency ratio by varying the above design parameters. FR4 substrate with dielectric constant 4.4 is chosen for design and fabrication. The dual design frequencies are 1.93GHz and 2.17GHz, covering the applications such as WCDMA, 3G mobile data terminals, and 4G LTE applications. The antenna is fed by a 50› coaxial probe. The simulation of the antenna is performed using ANSOFT HFSS and analyzed for return loss, VSWR and radiation pattern. The antenna is fabricated and tested for impedance matching and radiation characteristics. The simulation and experimental results show that the antenna worked well at desired dual frequencies. The impedance matching is well at both frequencies (VSWR < 2). Though, the measured radiation pattern is unidirectional in co-polarisation, nearly omnidirectional (butter∞y) pattern is obtained in cross-polarisation and gain is about 5.54dB at 1.93GHz and 8.23dB at 2.17GHz. Also, the design is well suited for small frequency ratio dual frequency applications.

A Novel Small Director Array for Slot Loop Antenna for LTE Application

A small director array for the slot loop antenna is described in this letter. The antenna consists of five elements, a planar reflector, a driven slot loop antenna, and three director arrays. Generally, the Yagi antenna can only work in a narrow band, but the proposed director array that is composed of nine rectangle loop elements can enhance antenna gain over a broad band. Simulation results show that, with this structure, the proposed antenna has a high gain greater than 11 dBi from 1.7 to 2.7 GHz, which covers the LTE band. The S11 is less than -10 dB within the working band. The measured results agree well with the simulation results.

A compact quadrature coupler on GaAs IPD process for LTE applications

A compact quadrature coupler on GaAs IPD process for LTE applications

Application of 3GPP LTE and IEEE 802.11p Systems to Ship Ad-Hoc Network with the Existence of ISI

In order to provide high data rate and real time services under maritime environment, link-level performance of ship ad-hoc network (SANET) based on 3GPP LTE and IEEE 802.11p (WAVE) specifications are investigated and discussed in this paper. The measured maritime channel, whose delay spread is longer than the length of guard interval (GI) of both 3GPP LTE and IEEE 802.11p specifications, is adopted for the link-level simulations. For the purpose of eliminating inter-symbol interference (ISI) due to insufficient GI length, double antenna pattern (DAP) scheme and advanced time-domain decision-feedback equalizer (DFE) are proposed for LTE and WAVE systems, respectively. The proposed DFE removes the ISI in a same manner as the residual inter-symbol interference cancellation (RISIC) algorithm, but the inter-carrier interference (ICI) is reduced via cyclicity removal instead of cyclicity restoration used in the RISIC algorithm. Compared with existing schemes, our proposed DFE is a robust technique to overcome the severe ISI channel which has a comparatively large delay spread. Based on simulation results, not only comparisons between systems are discussed, but also some reformative suggestions are given.

A 6th order wideband active-RC LPF for LTE application

A low power, highly linear active-RC filter is presented. This filter is synthesized from a low pass 6 order Chebyshev RLC ladder, and exhibits a reconfigurable bandwidth (10 MHz, 50 MHz). In order to meet the high cutoff frequency (50 MHz) and strict adjacent channel rejection requirements, a novel operational amplifier based on a new compensation technique is used, which optimizes high frequency filter performance and minimizes current consumption. This filter is fabricated in a 0.18 μm CMOS process, the measurement results indicate that the filter provides 10 MHz and 50 MHz selectable bandwidth, and excellent adjacent channel rejection: −15.3 dB at 12.5 MHz with 10 MHz cutoff frequency, −8.3 dB at 60 MHz with 50 MHz cutoff frequency, three times out-band rejection more than 60 dB while the in-band ripple is less than 1 dB.

Second-Order Cyclostationarity of Mobile WiMAX and LTE OFDM Signals and Application to Spectrum Awareness in Cognitive Radio Systems

Spectrum sensing and awareness are challenging requirements in cognitive radio (CR). To adequately adapt to the changing radio environment, it is necessary for the CR to detect the presence and classify the on-the-air signals. The wireless industry has shown great interest in orthogonal frequency division multiplexing (OFDM) technology. Hence, classification of OFDM signals has been intensively researched recently. Generic signals have been mainly considered, and there is a need to investigate OFDM standard signals, and their specific discriminating features for classification. In this paper, realistic and comprehensive mathematical models of the OFDM-based mobile Worldwide Interoperability for Microwave Access (WiMAX) and third-Generation Partnership Project Long Term Evolution (3GPP LTE) signals are developed, and their second-order cyclostationarity is studied. Closed-from expressions for the cyclic autocorrelation function (CAF) and cycle frequencies (CFs) of both signal types are derived, based on which an algorithm is proposed for their classification. The proposed algorithm does not require carrier, waveform, and symbol timing recovery, and is immune to phase, frequency, and timing offsets. The classification performance of the algorithm is investigated versus signal-to-noise ratio (SNR), for diverse observation intervals and channel conditions. In addition, the computational complexity is explored versus the signal type. Simulation results show the efficiency of the algorithm is terms of classification performance, and the complexity study proves the real time applicability of the algorithm.

Wideband Shorted Patch Antenna With a Modified Half U-Slot

A small wideband patch antenna with a modified half U-slot is presented. The antenna has an impedance bandwidth of 40% $({ S}_{11} , which is from 1.72 to 2.58 GHz. The antenna size is electrically and physically small, which is $0.012\lambda_{0}^{2}$ and 240 mm $^{2}$ , respectively. The proposed small antenna has good radiation characteristics, with a peak gain of 2 dBi. The proposed antenna is suitable for small wireless devices with the applications of Wi-Fi, Bluetooth, UMTS, GSM 1800, PCS 1900, and LTE.

Matrix Inversion Algorithm: Applications in High Speed MIMO LTE Receiver

Matrix inversion algorithm acting an important role in MIMO wireless communication.In this paper, we presenta matrix inversion algorithm and it’s applications in the high speed MIMO LTE receiver which is based on floating point DSP. Matrix operations are the most costly computational module within MIMO receivers but a matrix inversion algorithm is very easy to compute and significantly reduce the computational module cost. We will demonstrate the MIMO LTE applications for reducing the module cost by square matrix inversion algorithms.

Compact Dual-Band Dual-Polarized Antenna for MIMO LTE Applications

A system of two dual-band dual-polarized antennas is proposed. It operates in two bands, 700 to 862 MHz and 2.5 to 2.69 GHz, thereby making it suitable for LTE applications. The design is composed of two compact orthogonal monopoles printed close to each other to perform diversity in mobile terminals such as tablets or laptops. For each band, two orthogonal polarizations are available and an isolation higher than 15 dB is achieved between the two monopoles spaced byλ0/10 (whereλ0the central wavelength in free space of the lower band). A good agreement is observed between simulated and experimental results. The antenna diversity capability is highlighted with the calculation of envelope correlation and mean effective gain for several antennas' positions in different environment scenarios.

Multiband Planar Monopole Antenna for LTE MIMO Systems

A novel multiband-printed planar monopole antenna for LTE multi-input and multi-output (MIMO) application is proposed. A meandering microstrip line-loaded monopole antenna with multiband characteristic is presented. The proposed antenna provides five frequency bands for LTE application, covering 0.7, 1.7, 2.1, 2.3, and 2.5 GHz. In order to provide low mutual coupling and envelope correlation, two of the antennas are combined with orthogonal polarizations. The mutual coupling of the antenna is lower than −13 dB across the operation bands. Both the simulated and measured results are shown to illustrate the performances of the proposed antenna.

A compact slot inverted‐F antenna to be embedded in the laptop computer for LTE/WWAN applications

AbstractA slot inverted‐F antenna with multiband operations for long‐term evolution (LTE700/2500) and penta‐band wireless wide area network (WWAN) applications is presented. The antenna fabricated on a direct bond copper Al2O3 substrate consists of multibranch strips and a slot which occupy a compact size of merely 97(L) × 11.2(W) × 0.5(H) mm3 to be easily embedded in the laptop computer as an internal antenna. By properly designing the multibranch inverted‐F antenna, three bands covering 659–973 MHz, 1689–2179 MHz and 2449–2779 MHz for the LTE700, GSM850/900, DCS/PCS/UMTS, and LTE2500 operations are achieved with good radiation efficiencies. Thus, the proposed antenna is well suitable to be embedded in the laptop computer for the LTE and WWAN applications. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26131

An all digital PLL with an active inductor DCO for LTE applications in 0.13 μm CMOS

In this paper, we propose a low-power all digital phase-locked loop with a wide input range, and a high resolution TDC that uses phase-interpolator and a time amplifier. The resolution of the propo...

Design of a decoupled MIMO antenna for LTE applications

A compact multiple-input-multiple-output antenna array at 700 MHz has been proposed for long-term evolution-standardized handsets. A simple shunt element-based decoupling technique has been used to realize high isolation between the strongly coupled antenna elements. The antennas with and without decoupling have been evaluated for envelope correlation coefficient, radiation efficiency, and channel capacity characteristics. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:582–586, 2011; View this article at wileyonlinelibrary.com. DOI 10.1002/mop.25766

A Low Distortion and Low Noise Differential Amplifier Suitable for 3G LTE Applications Using the Even- and Odd-Mode Impedance Differences of a Bias Circuit

A low distortion and low noise differential amplifier using the difference between the even- and odd-mode impedances is proposed. In order to realize an amplifier with high OIP3 and low NF characteristics, the impedance of the bias circuit should be low ( 4kΩ) at the carrier frequency. Although the frequency response of the bias circuit impedance can only meet these conditions with difficulty, owing to the 20MHz Tx signal bandwidth for 3G LTE, the proposed amplifier can achieve the impedance difference using the properties of a differential configuration where the difference frequency signal is the even-mode and the carrier frequency is the odd-mode. It has been demonstrated that the NF of the proposed amplifier, which has been fabricated in 0.18μm SiGe BiCMOS technology operating at 2.14GHz, can be kept to 1.6dB or less and an OIP3 of 9.0dBm can be achieved, which is 3dB higher than that of a conventional amplifier, in the condition where the power gain is greater than 18dB.

LTE and near-LTE lighting plasmas

High-pressure mercury lamps, metal halide arc lamps, high-pressure sodium lamps, xenon short-arc lamps, xenon flashlamps, and microwave-excited metal halide lamps are extremely important commercial applications of LTE and near-LTE plasma physics. The author outlines in very brief form the basic plasma science in such light sources. The factors controlling the power balance and the luminous efficacy of such sources are discussed. Current research in modeling these complex plasma devices is described. This has reached the stage that successful CAD models are available for new-product design in mercury and high-pressure sodium lamps, but not yet for metal halide lamps. The behavior of electrodes is discussed as an important practical determinant of lamp life. Directions of future research and development are briefly discussed. >