Austin Kim

The compact quad-band mobile handset antenna for the LTE700 MIMO application

Fig. 3 shows the measured and simulated return loss of the proposed antenna. The lower band is tuned at about 770 MHz and has a bandwidth (1:3 VSWR) of 70 MHz (Antenna 1:735–810MHz, Antenna 2:740–800MHz), which satisfies the operating bandwidth of the LTE band class 13 (746–787 MHz). The GPS band has a bandwidth (1:3 VSWR) of 200 MHz (1410–1610MHz), which satisfies the operating bandwidth of the GPS at L1 band (1565∼1585MHz). The PCS and UMTS band has a bandwidth (1:3 VSWR) of 400MHz (1790–2190) PCS and UMTS band (1810–2170MHz). The obtained bandwidths meet the bandwidth requirement of the LTE band class 13, GPS at L1 band, PCS and UMTS mobile handset systems. The average gain was measured in the Reverberation 3D chamber [2] and the corresponding radiation patterns are shown in Fig. 4. Table I. shows the average gain data of the whole frequency bands and table II. shows the important factors for LTE700 MIMO performance. When the suspended line is applied to the proposed antennas, those have better performance compared to antennas excluding suspended line. Suspended line between antennas is able to operate like a band stop filter. This is an important factor to maintain a high isolation. The proposed antennas connected by suspended line can easily be applied to commercial RF devices such as a USB dongle and an express card for MIMO systems. The demands of MIMO system will significantly increase in the near future. Proposed structure of the antennas and suspended line is very promising.

System-Level Time-Domain Behavioral Modeling for A Mobile WiMax Transceiver

The time-domain baseband equivalent model for a mobile WiMax, IEEE 802.16e RF transceiver has been addressed in this paper. The baseband equivalent model is built up based on complex signals and spectrum. Nonlinearity up to the fifth order harmonics is considered, and noise characteristics are modeled in time domain for amplifiers and mixers. The time-domain phase noise is also implemented as part of PLL-based local oscillators. The non-ideal parameters, DNL and INL, are defined to describe non-linearity of ADC and DAC. With this behavioral models implemented on Matlab/Simulink environment, the performance of a complete mobile WiMax transceiver can be evaluated and predicted before an actual hardware design

Analysis of mobile phone's immunity to electrostatic discharge soft failures

A technique for the analysis of mobile phones immunity to the electrostatic discharge (ESD) soft failures is proposed. First, a mobile phone, ESD simulator and ESD testing setup are modelled and then the simulation is performed using time-domain full-wave electromagnetic simulator. The proposed technique is applied to the analysis of ESD soft failure of mobile phones and the root causes of the ESD soft failure are investigated. ESD voltages obtained from simulation are compared to that from measurement. Also, improvement in the frequency of occurrence of ESD soft failure by the application of countermeasures derived from ESD simulation result is presented.

Performance improvement methodology of isolation in a dual-standby mobile phone by optimizing antenna topology and position

The mutual coupling between two internal antennas using same communication band in simplified dual-standby simulation model has been researched. Furthermore, the excited current distributions on the PCB and the electric field distributions in the near field have been investigated as the cause of coupling. In terms of antenna type, PIFA type antenna was better than monopole type in the isolation viewpoint in dual-standby phone (max. 8~9 dB). Also, in terms of feed position, position 1 and 4 was the best through all positions which can be combined from 6 feed positions of Fig. 1. The coupling difference between min. and max. was 4.5 dB in monopole, 10.8 dB in PIFA. The results will be used to guidelines in the initial stage of phone design for achieving new specifications with respect to isolation of dual-standby phone.

Dual-port LCP multi-band antenna for Wibro/mWiMax MIMO, Bluetooth and GPS applications in mobile phone

The proposed LCP MMMB Wibro MIMO antenna has a good bandwidth (VSWR 3:1) performance at the band of Wibro1/Bluetooth and GPS/Wibro2. It is also got the average radiation efficiency more than 30% except Wibro1. However, it could be improved by a little antenna matching tuning on the mobile handset. This antenna can be also used switchable because of two signal lines.

An accurate modeling technique for the estimation of the radiation performance of commercial mobile phone with use of the M-CAD data

This paper presents an accurate modeling technique to estimate radiation performance of commercial bar type mobile phone by using the mechanical-CAD data. In particular, important parts of radiation performance such as a LCD module, a PCB, antenna feed area, a FPCB and an EMI sheet are finely considered to model. Simulation results of the radiation efficiency and specific absorption rate (SAR) are compared with the measurement data at GSM/DCS bands to verify the accuracy of the simulation model.

The compact Quad-band PCB embedded antenna for mobile handsets

This paper presents a novel PCB embedded antenna for GSM900/DCS1800/PCS1900/UMTS2100 band operations. The proposed antenna is composed of conventional loop and PIFA antenna. This antenna occupies a compact area, 30times15 mm2 only and does not need the thickness. In order to reduce the effective antenna length for the resonance of the GSM900 band, the electrical coupling between the ground of PCB and antenna radiator is used.

An electromagnetic modeling oriented RF co-simulation platform for the mobile handset application

A RF co-simulation platform consisting PCB electromagnetic (EM) modeling and behavioral modeling has been proposed for the wireless handset application. Through integration of EM PCB pattern models, RF component models and RF transceiver behavioral models, complete RF co-simulation could be accomplished. Established simulation platform has been applied to 1800 MHz CDMA mobile phone (Korean PCS) and shows that simulation results are very close to measurement results. This co-simulation platform enables predicting RF performance before prototyping through analysis of S-parameter characteristics and overall RF functionalities such as ACPR FER and STD.

Calculation of total isotropic sensitivity considering digital harmonic noise of mobile phone

This paper introduces an efficient method to calculate the total isotropic sensitivity (TIS) of a mobile phone. The method is implemented by using the EM simulation, the digital signal modeling and the RF link budget simulation. By considering digital harmonic noise, the accuracy of the TIS calculation can be increased. Simulation results for the phone structure show the availability of this proposed method.

Design and analysis of multi-band antenna for mobile handset applications

Multi-band antenna covering GSM850/GSM900/DCS1800/PCS1900/UMTS2100 in mobile phones is presented. The proposed antenna is kind of a modified PIFA which consists of PIFA and T-branch. The bandwidth in low and high band is achieved using gap coupling between low and high band arm. And also bandwidth in low-band is improved by the coupling between T-branch and metal ring along the edge of the housing. Experimental and simulation results using SEMCAD are presented.