Planar Monopole Antenna Research Articles

Planar Internal LTE/WWAN Monopole Antenna for Tablet Computer Application

By using a T-shaped parasitic shorted strip, this work presents a planar coupled-fed U-shaped monopole antenna with eight-band LTE/WWAN operation in tablet computers. The obtained impedance bandwidths across dual operating bands approach 281 MHz and 1088 MHz at the LTE and WWAN bands, respectively. The proposed uniplanar antenna reduces the antenna size by at least 20% since the overall antenna size is only 50×15×0.8 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . The measured peak gains and antenna efficiencies are approximately 2.9/5.4 dBi and 72/80% for the LTE/WWAN bands, respectively. Moreover, with a compact structure, the proposed planar antenna can be deposited inside the tablet computer and complies with the body specific absorption rate (SAR) requirement (1.6 W/kg for 1-g body tissue) for practical applications.

Compact MIMO Antenna for Portable Devices in UWB Applications

A compact multiple-input-multiple-output (MIMO) antenna with a small size of 26×40 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> is proposed for portable ultrawideband (UWB) applications. The antenna consists of two planar-monopole (PM) antenna elements with microstrip-fed printed on one side of the substrate and placed perpendicularly to each other to achieve good isolation. To enhance isolation and increase impedance bandwidth, two long protruding ground stubs are added to the ground plane on the other side and a short ground strip is used to connect the ground planes of the two PMs together to form a common ground. Simulation and measurement are used to study the antenna performance in terms of reflection coefficients at the two input ports, coupling between the two input ports, radiation pattern, realized peak gain, efficiency and envelope correlation coefficient for pattern diversity. Results show that the MIMO antenna has an impedance bandwidth of larger than 3.1-10.6 GHz, low mutual coupling of less than -15 dB, and a low envelope correlation coefficient of less than 0.2 across the frequency band, making it a good candidate for portable UWB applications.

Triple‐Band Cpw‐Fed Planar Monopole Antenna for Wlan/Wimax Application

A triple‐band planar monopole antenna is presented in this article. The antenna consists of three strips which correspond to operating frequency bands of 2.4, 3.5, and 5.8 GHz. The proposed antenna has been designed, simulated, and fabricated on 20 × 38 mm2 FR4 board. There is good agreement between simulation and measurement results in terms of return loss and radiation pattern. The proposed antenna provides measured −10 dB bandwidths of 200 MHz for the 2.4 GHz (from 2.36 to 2.56 GHz); 620 MHz for the 3.5 GHz (from 3.48 to 4.10 GHz); and 1.38 GHz for 5.8 GHz (from 5.65 to 7.03 GHz). Moreover, the antenna provides the measured gain of 4.73, 1.66, and 3.28 dBi for 2.4, 3.5, and 5.8 GHz, respectively. The radiation characteristics have proven that the proposed antenna seems to be a good potential candidate for WLAN/WiMAX applications. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2209–2214, 2013

Low SAR planar monopole antenna for wireless communication applications

Simple internal multiband monopole antenna with low specific absorption rate (SAR) for most wireless communication applications is presented in this paper. The proposed antenna is an unequal arms monopole antenna with a meander stripoin the other substrate side. The antenna has a simple structure and it is sufficiently small in size to be easily fitted on the housing of a mobile phone or a universal serial bus (USB) dongle with size 20 × 50 × 0.8 mm3. The antenna is designed to operate in different bands to cover most of allocated wireless communication bands in the frequency range from 0.9 to 6 GHz. The proposed antenna has an acceptable average gain of about 2.75 dBi and an average efficiency of about 85% while providing a monopole radiation pattern in both horizontal and elevation planes, with average half-power beam width of 65° in the elevation plane. The simulation and the experimental results of the antenna are in agreement. The SAR in the human head is investigated by using CST 2012 Microwave Studio Hugo Voxel Model.

Microstrip feed spanner shape monopole antennas for ultra wide band applications

An optimized design for the spanner shape regular hexagonal monopole (RHM) patch antennas has been reported to yield ultra wide band (UWB) impedance bandwidth. Impedance and radiation characteristics are presented and discussed. From the results, it has been observed that, the impedance bandwidth, defined by 10 dB return loss, can reach a value of 8.63GHz. A rectangular slit in the radiating patch is used to reduce the lower-edge frequency resulting in improved bandwidth. This technique yields the ability to construct a smaller antenna in comparison to a simple printed planar monopole antenna for a given frequency range. The printed metallic patch is defected for increasing the operating bandwidth. The antennas considered in this paper operate between 2.95 GHz to 11.58 GHz, making them suitable for numerous DECT, WLAN, remote sensing, radar, imaging, localization and medical applications. The etched area of the antenna can be used for communication circuit components.

Dual‐band coplanar waveguide‐fed smiling monopole antenna for WiFi and 4G long‐term evolution applications

A novel ‘coplanar waveguide’-fed planar monopole antenna with dual-band operation for WiFi and ‘long-term evolution 4G (LTE)’ applications is presented. The simple antenna's geometry is composed of a circular radiating patch with a smiling slot, and it occupies a small size of 41.6(L) × 28.38(W) × 1.52(h) mm3. Two operating bands covering 2.3–3.0 and 4.7–5.9 GHz are achieved by carefully optimising the position and size of a smiling slot. An antenna prototype has been manufactured and it has been characterised in terms of return loss and radiation pattern measurements in anechoic chamber exhibiting almost omnidirectional patterns and appreciable gain across the operating bands, being suitable for WiFi and 4G LTE applications.

Novel UWB Monopole Antenna With Band Notched Characteristics

A compact planar monopole antenna with band-notched characteristics suitable for Ultra Wideband (UWB) applications is presented. The proposed UWB microstrip-fed antenna consisting of U-shaped slots in both patch and the microstrip-feed line with a defected ground structure. This antenna is designed to cover the Federal Communication Commission (FCC) bandwidth for UWB applications (2.04-14.6 GHz), while showing tri band-notched characteristics in the frequency bands of: (3-4.3 GHz) used for WiMAX, (6.12-6.8 GHz) used for C-band uplink frequency and (8.7-9.2 GHz) used for aeronautical radio navigation. The proposed antenna is suitable for various narrow band wireless applications, satellite applications and radar applications. The proposed UWB antenna is simulated by using High Frequency Structural Simulator (HFSS).

Frequency-Tunable Monopole Antenna for Wimax Applications

This article presents a planar dual-band monopole antenna with a frequency-tunable band for use in wireless devices of the 2.4 and 3.4 GHz worldwide interoperability for microwave access (WiMAX) system. The antenna has two radiating branches acting as monopoles and resonating at around 2.4 GHz (lower band) and 3.4 GHz (higher band). A varactor is placed on the radiating branch responsible for the lower band. A very simple DC biasing circuit is designed for reverse-biasing the varactor. By varying the DC-bias voltages from 0 to 12 V for the varactor, the lower band of the antenna can be continuously tuned from 2.3 to 2.83 GHz, covering the frequency bands from 2.3 to 2.4 GHz and 2.5 to 2.7 GHz for the WiMAX system. The antenna has a small overall size of 40 × 35 × 0.8 mm3 with a compact radiator of only 14.5 × 8.2 mm2. The antenna performance in terms of reflection coefficient, radiation pattern, peak gain, and efficiency is studied using computer simulation. For verification of simulation results, the antenna is fabricated and measured. The feeding cable used in measurement causes substantial discrepancies between the simulated and measured simulation results. To study the cable effects, a computer simulation model is included for studies. With the cable model, the simulated and measured results agree very well. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1902–1907, 2013

Metamaterial-Based Design of Planar Compact MIMO Monopoles

A systematic design of planar MIMO monopole antennas with significantly reduced mutual coupling is presented, based on the concept of metamaterials. The design is performed by means of individual rectangular loop resonators, placed in the space between the antenna elements. The underlying principle is that resonators act like small metamaterial samples, thus providing an effective means of controlling electromagnetic wave propagation. The proposed design achieves considerably high levels of isolation between antenna elements, without essentially affecting the simplicity and planarity of the MIMO antenna.

Design of a new ultra wideband planar antenna for wireless communication systems

AbstractA new planar circular monopole antenna for ultra wideband (UWB) applications is presented. To achieve UWB characteristics, the proposed antenna is constructed by embedding the slot on the partial ground plane. The proposed antenna has been successfully simulated and measured. Experimental results indicate that the proposed antenna yields an impedance bandwidth of 2.3 up to 13 GHz with VSWR &lt; 2, which makes it suitable to operate not only for UWB bandwidth but also it can be used also for WLAN application. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1335–1338, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27584

Highly compact UWB printed monopole antennas with different ground plane structures

AbstractThis article presents highly compact‐sized, low‐profile, and planar monopole antennas for ultra‐wideband (UWB) operations.The two proposed antennas' structures consist of the circular radiating patch with microstrip‐fed monopole structure and coplanar waveguide‐fed (CPW) monopole structure. By properly selecting positions and dimensions of the embedded slots in the radiating patch and ground planes, wide impedance bandwidths are achieved. The numerical and experimental results show that the designed antennas can operate over UWB band groups 2, 3, 4, and 5 and satellite communications. The designed antennas have the simple uniplanar structures and occupy small size of 11 × 16 mm2 including the finite ground CPW feeding mechanism and partial ground microstrip line feeding mechanism. In addition, acceptable radiation characteristics are obtained over the operating bands. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1191–1196, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27538

Planar monopole antenna for multiband wireless applications

In this article, a new multiband planar monopole antenna for mobile devices application is presented. The proposed antenna operation is on the basis of using two radiation spiral strips and two slots on the ground plane. This antenna covers eight standard frequency bands including: GSM900, DCS1800, PCS1900, UMTS, WiBro, Bluetooth, WiMax, and WLAN. It occupies the area of 40 mm × 18 mm excluding the ground plane. A prototype of this antenna has been fabricated and its parameters have been measured. There is a good agreement between the measured and simulated results. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:966–970, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27497

Design and Analysis of Modified Planar Monopole Antenna for UWB Applications with Truncation in Ground Plane

In the proposed paper, a planar monopole antenna with modified patch and truncated ground plane for Ultra wideband (UWB) applications is presented. The radiating element of the proposed antenna is fed by a 50 Ω microstrip line. Truncation in the ground plane is made for better impedance matching. It is found that by making steps in the ground plane, return loss characteristics and hence the VSWR is improved. The antenna parameters and performances have been investigated by using commercially available CST Microwave Studio software. Simulation and measurement results show that the proposed antenna provides an ultra wide bandwidth, completely covering the range set by the Federal Communication Commision (FCC) for UWB operations (3.1 GHz to 10.6 GHz).The antenna is of low profile and exhibits omnidirectional radiation pattern and high gain for the entire bandwidth.

Microstrip Line-fed Printed Planar Monopole Antenna for UWB Applications

In this study, a microstrip line-fed printed planar monopole antenna for ultra-wideband applications is presented. The proposed antenna is composed of an annular ring fed by a microstrip line and a partial ground plane. It occupies 39 × 40 × 1.6 mm3 on the FR4 substrate material. The measured impedance bandwidth of the realized antenna is from 2.6 to 12.3 GHz (4.7:1, 129.35 %) for VSWR ≤ 2. It has an average gain of 3.67 dBi with a maximum gain of 5.52 dBi. Moreover, the antenna exhibits stable omnidirectional radiation patterns within the operating band. Details of the proposed antenna design are presented and discussed.

Capacitive Sensing of Antenna Loading With an R–C Voltage Divider in a Tunable Antenna

This paper presents a capacitive sensor for antenna applications. The sensor is based on measuring voltage in a voltage divider made of a resistor and a capacitor formed in an antenna structure. The purpose of the device is to detect when the user of a mobile device holds a finger near the antenna element and allow triggering of compensation measures to regain antenna performance. A planar monopole antenna with an impedance tuning element was constructed for this purpose, and measurements showed that 10% of lost total efficiency can be regained by applying retuning. The sensor can measure capacitance changes of 5 fF and detect a human finger at up to a distance of 1 cm. Some design issues and caveats are also discussed.

Wideband Fan-Beam Low-Sidelobe Array Antenna Using Grounded Reflector for DECT, 3G, and Ultra-Wideband Wireless Applications

A low-sidelobe fan-beam wideband linear array antenna employing a nonparasitic grounded reflector is presented. This fan-beam antenna is achieved using a six-element conventional planar monopole array antenna and feed network, which together produce sidelobes at - 26 dB. Dolph-Tschebyscheff distribution is employed, and a broadband array feed network is designed to satisfy beneficial input impedance bandwidth requirements in the frequency range 1.7-2.2 GHz. Therefore, this array covers applications of GSM-DCS2, DECT, and 3G. Combining planar monopole antenna as an array with nonparasitic grounded reflector allows an advantageous fan beam pattern to be generated. H-plane 3-dB beamwidths are controllable using grounded reflector height. In addition, the results are compared with and without reflector array antenna.

사각 루프와 T자형 패치를 결합한 광대역 평면형 모노폴 안테나 설계 및 SAR 분석

본 논문에서는 다중 대역 서비스를 위한 평면형 모노폴 안테나를 설계 및 제작하였다. 제안된 안테나는 기본적인 사각 루프 구조를 내부로 접어 안테나의 크기를 소형화 시켰으며, T자형 패치의 끝단의 중앙 부분과 내부로 접은 사각 루프 선로에서의 커플링 현상을 이용하여 3.9 GHz 대역에서 추가 공진을 만들었다. 또한 사각 루프 형태의 모노폴 안테나에 T자형 사각 패치를 삽입시킴으로써 광대역 주파수 특성을 나타나도록 유도하였으며, 내부로 접은 사각 루프의 선로들의 간격 및 길이와 T자형 패치의 가로 길이를 조정함에 따라 주파수 특성을 최적화 하였다. 제안하는 안테나는 <TEX>$40{\times}60{\times}1.6mm^3$</TEX> 크기의 비유전율 4.4인 FR-4 기판 위에 설계하였으며, 급전은 임피던스 <TEX>$50{\Omega}$</TEX>의 마이크로스트립 선로를 사용하였다. 측정 결과, VSWR 2:1 기준으로 대역폭은 162 MHz(815~977 MHz)와 2,530 MHz(1,430~3,960 MHz)으로 측정이 되었다. 제안된 안테나의 전자파 흡수율(SAR)을 알아보기 위하여 1 g 및 10 g 평균 SAR을 계산 및 측정을 실시하였으며, 모의실험 결과, 1 g 평균은 1.044 W/kg, 10 g 평균은 0.718 W/kg으로 SAR 기준치인 1.6 W/kg(1 g 평균) 및 2.0 W/kg(10 g 평균)을 만족하는 결과를 보였다. In this paper, a broadband planar monopole antenna for multi-band services is proposed. The physical size of the proposed antenna is miniaturized by folding a rectangular loop. And a resonance point in the 3.9 GHz band is reduced by a coupling phenomenon with the central part of the T-shaped patch and the folded rectangular loop. In addition, the T-shaped patch is inserted to the rectangular shaped monopole antenna due to deriving the broadband frequency characteristics. The frequency characteristic is optimized by adjusting the gap and length of the folded rectangular loops and a transverse diameter of the T-shaped patch. The antenna dimensions including the ground plane are <TEX>$40{\times}60{\times}1.6mm^3$</TEX>. It is fabricated on the FR-4 substrate(<TEX>${\epsilon}_r$</TEX>=4.4) using a microstrip line of <TEX>$50{\Omega}$</TEX> for impedance matching. In the measured result, the bandwidth corresponding to the VSWR of 2:1 is 162 MHz(815~977 MHz) and 2,530 MHz(1.43~3.96 GHz). For analyzing the human effect by the proposed antenna, 1 g and 10 g averaged SARs are simulated and measured. As the simulated results, 1 g-averaged SAR is 1.044 W/kg, and 10 g-averaged SAR is 0.718 W/kg. This result are satisfied by the SAR guidelines which are 1.6 W/kg(1 g-averaged) and 2.0 W/kg(10 g-averaged).

스파이럴 구조 기생 소자와 L자형 공진기를 갖는 모노폴 안테나 설계 및 구현

본 논문에서는 기생 소자의 커플링 현상을 이용하여 다중 대역 특성을 나타내기 위한 평면형 모노폴 안테나를 설계 및 제작하였다. 제안된 안테나는 단일 공진이 발생하는 사각 패치를 기본으로 다중 대역 특성을 얻기 위해 기생 소자를 삽입하였다. 기생 소자는 안테나 크기의 소형화와 다중 공진 특성을 나타내기 위해 스파이럴 구조를 사용하였으며, 각각의 설계 파라미터들을 이용하여 주파수 특성을 최적화 시켰다. 또한, via-hole을 통해 접지면에 연결된 L자 형태의 공진기를 급전선 양쪽에 삽입함으로써 서비스 대역 이외에 사용되지 않는 주파수 대역을 차단하였다. 사용된 기판은 크기가 <TEX>$40{\times}60{\times}1mm^3$</TEX>이고, 비유전율 4.4인 FR-4 기판 위에 설계되었으며, 급전은 임피던스 <TEX>$50{\Omega}$</TEX>의 마이크로스트립 선로를 사용하였다. 측정 결과, 1.714~2.496 GHz, 2.977~4.301 GHz, 4.721~6.315 GHz 대역에서 -10 dB 이하의 반사 손실 특성을 나타냈으며, 전방향의 방사 패턴을 나타냈다. In this paper, we designed and implemented the planar monopole antenna using the coupling effect for the multi-band characteristic. A parasitic element for the multi-band characteristic based on a rectangular patch with single resonance is inserted. Spiral shaped parasitic element is used for minimizing the antenna size and obtaining the multi-resonance characteristic. The frequency characteristics are modified and optimized by varying specific parameters. By inserting an L-shaped resonator at both sides of the feed line which connected through the via hole to the ground plane, unnecessary frequency bands are eliminated. Proposed antenna dimension is <TEX>$40{\times}60{\times}1mm^3$</TEX>. It is fabricated on the FR-4 substrate(<TEX>${\varepsilon}_r$</TEX>=4.4) using a microstrip line of <TEX>$50{\Omega}$</TEX> for impedance matching. By measurement results, the characteristic of the return loss under -10 dB are 1.714~2.496 GHz, 2.977~4.301 GHz, and 4.721~6.315 GHz, and the radiation patterns have omni-directional shapes.

A multiwideband planar monopole antenna for 4G devices

AbstractThis article presents a compact multiband planar antenna designed for mobile phone applications.The antenna performance is achieved by designing a planar monopole antenna into distributed radiating elements. The proposed antenna is comprised of a chopped circular radiator appended with a meander line and an L‐strip coupled element, which is an extension of the ground plane. The combination of a chopped circular patch and L‐shaped coupling strip residing on the top side generates lower band while upper band resonances are attained separately by chopped circular resonator and meander line elements. The antenna shows a planar structure which occupies an area of 56 × 17.6 mm and can be directly printed onto a circuit board at low cost making it especially suitable for mobile phone applications. The manufactured antenna is experimentally verified and covers several wireless communication bands, such as LTE 750, GSM 850, GSM 900, DCS, UMTS‐2110, Bluetooth, WLAN, WiMAX, and UWB. The high frequency structure simulation is used to design and analyze the antenna performance, and a practical structure was fabricated and tested. The measured and simulated return loss show good agreement. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:589–593, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27360

Compact Ultrawideband Monopole Antenna With an Inverted-L-Shaped Coupled Strip

We present a compact, ultrawideband, and planar monopole antenna that is composed of a C-shaped radiator and an inverted-L-shaped coupled strip extending from the ground plane. A wideband impedance bandwidth is achieved; the monopole antenna itself operates over a higher frequency range, while an increased electrical length due to the combination of the radiating element with the L-shaped strip operates over a lower frequency range. Furthermore, a coupling effect between both structures improves the impedance matching. The impedance bandwidth measured from 2.3 to 10.8 GHz includes the WiMAX (2.30-2.39, 2.50-2.69, 3.4-3.8, and 5.72-5.85 GHz), WLAN (2.4-2.48 and 5.15-5.875 GHz), S-DMB (2.605-2.655 GHz), and UWB (3.1-10.6 GHz) bands.