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235 GHz on‐chip antenna with miniaturised AMC loading in 65 nm CMOS

2017; Institution of Engineering and Technology; Volume: 12; Issue: 5 Linguagem: Inglês

10.1049/iet-map.2017.0710

1751-8733

Hua Zhu, Xiuping Li, Weiwei Feng, Jun Xiao, Jianhua Zhang,

Microwave Engineering and Waveguides

IET Microwaves, Antennas & PropagationVolume 12, Issue 5 p. 727-733 Research ArticleFree Access 235 GHz on-chip antenna with miniaturised AMC loading in 65 nm CMOS Hua Zhu, Hua Zhu School of Electronic Engineering, University of Posts and Telecommunications, Beijing, People's Republic of China Beijing Key Laboratory of Work Safety Intelligent Monitoring, Beijing University of Posts and Telecommunications, 100876 Beijing, People's Republic of ChinaSearch for more papers by this authorXiuping Li, Corresponding Author Xiuping Li xpli@bupt.edu.cn School of Electronic Engineering, University of Posts and Telecommunications, Beijing, People's Republic of China Beijing Key Laboratory of Work Safety Intelligent Monitoring, Beijing University of Posts and Telecommunications, 100876 Beijing, People's Republic of ChinaSearch for more papers by this authorWeiwei Feng, Weiwei Feng School of Electronic Engineering, University of Posts and Telecommunications, Beijing, People's Republic of China Beijing Key Laboratory of Work Safety Intelligent Monitoring, Beijing University of Posts and Telecommunications, 100876 Beijing, People's Republic of ChinaSearch for more papers by this authorJun Xiao, Jun Xiao School of Electronic Engineering, University of Posts and Telecommunications, Beijing, People's Republic of ChinaSearch for more papers by this authorJianhua Zhang, Jianhua Zhang School of Information and Communication Engineering, University of Posts and Telecommunications, Beijing, People's Republic of ChinaSearch for more papers by this author Hua Zhu, Hua Zhu School of Electronic Engineering, University of Posts and Telecommunications, Beijing, People's Republic of China Beijing Key Laboratory of Work Safety Intelligent Monitoring, Beijing University of Posts and Telecommunications, 100876 Beijing, People's Republic of ChinaSearch for more papers by this authorXiuping Li, Corresponding Author Xiuping Li xpli@bupt.edu.cn School of Electronic Engineering, University of Posts and Telecommunications, Beijing, People's Republic of China Beijing Key Laboratory of Work Safety Intelligent Monitoring, Beijing University of Posts and Telecommunications, 100876 Beijing, People's Republic of ChinaSearch for more papers by this authorWeiwei Feng, Weiwei Feng School of Electronic Engineering, University of Posts and Telecommunications, Beijing, People's Republic of China Beijing Key Laboratory of Work Safety Intelligent Monitoring, Beijing University of Posts and Telecommunications, 100876 Beijing, People's Republic of ChinaSearch for more papers by this authorJun Xiao, Jun Xiao School of Electronic Engineering, University of Posts and Telecommunications, Beijing, People's Republic of ChinaSearch for more papers by this authorJianhua Zhang, Jianhua Zhang School of Information and Communication Engineering, University of Posts and Telecommunications, Beijing, People's Republic of ChinaSearch for more papers by this author First published: 12 March 2018 https://doi.org/10.1049/iet-map.2017.0710Citations: 12AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract In this study, an on-chip antenna with miniaturised artificial magnetic conductor (AMC) structure loading is designed and fabricated in the 65 nm complementary metal oxide semiconductor process at 235 GHz. The proposed on-chip antenna consists of a double-layer dipole and miniaturised AMC with wide bandwidth and low-backward radiation. A quarter square loop structure for the miniaturised AMC is designed and analysed by the current and electric field distributions. The simulation results show that the miniaturised AMC has a similar resonant frequency and lower reflection loss compared with the original one. The die area of the proposed antenna is . The measurement of the −10 dB impedance bandwidth is 81 GHz (200–281 GHz). The gain of the antenna is up to 0 dBi at 235 GHz. By loading the miniaturised AMC, the on-chip antenna can obtain higher gain, wider bandwidth than that loading the original one. Good agreement can be well observed between the simulated and measured results. 1 Introduction There has been a growing interest in the terahertz frequency range (0.1–10 THz) in the past few years for numerous applications, such as high data rate wireless communication, imaging, low-cost diagnostics, remote sensing, spectroscopy and quality control [[1], [2]]. Although wide bandwidth allows for attaining high data rates, the THz bands have a limitation in the transmission range due to high atmospheric attenuation. For front-end THz systems, whose operating frequency exceeds the limit of the silicon-based technologies, gain and efficiency of the antenna is rather crucial for achieving the on-chip antenna. During recent research, several on-chip antennas have been proposed to meet the demand of the THz antenna [[3]–[6]]. On-chip antennas suffer from higher losses, which are induced by backside power radiation and higher-order surface waves are excited due to the high dielectric constant and large thickness of the silicon substrate. There have been quite a few reported methods to suppress the losses. One method is to use thin membranes to fabricate Si or GaAs. Another method is to remove the semiconductor underneath the antenna to produce a cavity. These methods provide the low effective dielectric constant substrate for the antenna region [[7], [8]]. However, the extra process is required to increases the complexity and cost. The third method is to require additional elements for efficient couplings such as substrate lenses [[4]] or micro-machined horns [[9]]. However, these techniques increase the size of antennas. A metal reflector has been reported to improve antenna gain [[10], [11]]. A metal reflector needs to be placed at a quarter-wavelength from the antenna. However, the total thickness of the Si substrate for a typical complementary metal oxide semiconductor (CMOS) process is <, while a quarter-wavelength is about at 300 GHz. Therefore, no metal reflector can be added in the CMOS process. An artificial magnetic conductor (AMC) structure with periodic patches exhibits a phase reflection coefficient like a perfect magnetic conductor (PMC). The AMC structure has been an attractive area, which can replace a perfect electric conductor (PEC) adding an antenna for low-profile, wide bandwidth and high gain [[12], [13]]. Traditionally, the AMC structure has a unit-cell size of about half to a quarter-wavelength [[14]]. However, the practical applications are restricted to limited space, such as backing plane for antennas. In addition, the more AMC unit-cells are arranged in a limit space, the more stable performance of the AMC can be achieved. To overcome size limitation, a miniaturised AMC structure is designed. In this study, a novel THz on-chip antenna loading miniaturised AMC is designed and fabricated in the 65 nm CMOS process. The miniaturised AMC structure is designed to reduce backward radiation, enhance gain. The die area of the antenna is . The measurement of the −10 dB impedance bandwidth is around 81 GHz (200–281 GHz). The gain is 0 dBi at 235 GHz. The measurement results are in good agreement with the simulation results. This paper is organised as follows. Section 2 presents the geometry of the proposed miniaturised AMC structure and its analysis of current and electric-field distribution. Section 3 shows the integration and optimisation of double-layer dipole loaded miniaturised AMC structure. Section 4 demonstrates the simulated and measured results of the proposed antenna. The conclusion is given in Section 5. 2 Miniaturised AMC design The reflection coefficient of a plane wave incidence on the PEC is , which means the reflected wave can cancel with the incident wave. On the contrary, the AMC plane exhibits a reflection coefficient of , which means that the phase of the reflected wave is compared with the phase of the incident wave [[15]]. Fig. 1a shows a side view of the antenna loading AMC structure. On the top of the substrate, the frequency selective surface (FSS) pattern is placed in order to generate a resonant effect, and a metal plate is placed on the bottom of the substrate. The antenna loading AMC structure equivalent transmission line model is shown in Fig. 1b. The antenna is placed above the AMC plane, where the distance is . The thickness of the substrate is . When the antenna is incident by plane wave propagation, antenna radiation field at the z-plane can be expressed as (1) where is a radiation field upward by the antenna, is a radiation field downward by the antenna, is the amplitude of electric field, and k is the free space wave number. The reflection phase of the AMC is . Fig. 1Open in figure viewerPowerPoint Schematic and equivalent transmission line model of antenna loading AMC structure (a) Schematic of antenna loading AMC structure, (b) Equivalent transmission line model of antenna loading AMC structure If the radiation field reaches a maximum, satisfies the following equation: (2) From (2), if the reflection phase of the AMC is , . Therefore, the AMC plane can be placed on the same plane of the antenna. The AMC plane can produce a constructive reflection phase with the incident wave at a specified operating frequency band. To achieve the increasing radiation field (3) The standard 65 nm CMOS process technology is illustrated in Fig. 2a. The process provides eight copper metal layers (seven thin ones and one thick one). Each metal layer is separated by one SiO2 substrate and the fabricated chip is covered by a nitride passivation layer for protection purposes. Most AMC structures are structurally symmetric. According to the basic resonance mechanism, the smaller dimension determines the higher resonant frequency, while the larger one determines the lower resonant frequency. For symmetrical structures, their half structure has an equal impact in determining the resonant frequencies. Fig. 2b shows the unit-cell of the original AMC structure (AMC-A) consisted of two square loop structures and square patches on M1, ground on the bottom of the Si substrate. The thickness of the Si substrate is . The permittivity of silicon is 11.9 with a conductivity of 10 S/m. The design parameters of AMC-A include two square loop lengths (a and ), two loop widths (w and ), square patch length and periodicity (g). To miniaturise the structure, AMC-A is cut to three-quarters dimension to obtain AMC-B, as shown in Fig. 2c. The design parameters of AMC-B include a quarter square loop lengths ( and ), loop widths ( and ), a quarter square patch length and periodicity . The dimensions of the AMC are shown in Table 1. Fig. 2Open in figure viewerPowerPoint Evolution of the proposed AMC structure (a) Cross-sectional view of the CMOS process technology, (b) AMC-A, (c) AMC-B Table 1. Parameters of the AMC, μm Parameters Values Parameters Values a 41 w 2 31 2 17 1 23 1 19 g 43 12 25 To accurately characterise the reflection phase of wave incident on the AMC, the finite-element-method-based 3D full-wave electromagnetic solver, Ansoft HFSS, is used for the AMC simulation. The HFSS model to compute the reflection phase characteristics of the proposed AMC structure is shown in Fig. 3. This model is based on simulating scattering parameters of a single port air filled waveguide with two PEC and two PMC walls [[16]]. The propagating plane wave is polarised parallel to the PMC walls and normal to the PEC walls. The waveguide is terminated to the proposed AMC structure and the reflection phase is obtained by calculating the scattering parameter at the input of this single port waveguide. Fig. 3Open in figure viewerPowerPoint HFSS simulation model for an AMC-B plane (a) Geometry and wave-port excitation, (b) Perfect E-symmetry planes, (c) Perfect H-symmetry planes Fig. 4 shows the current distributions of both AMC-A and AMC-B with the same current scale at 235 GHz. It is noted that the current distribution of AMC-A is symmetrical along the line of the square loop and ground. The current distribution of AMC-B is similar to that of AMC-A at 235 GHz. Hence, three quarters of the square loop of AMC-A can be removed without significantly affecting the current paths. Fig. 5 shows the electric field distributions of the AMC-A and AMC-B at 235 GHz. The electric amplitude in the Si structure is smaller than that in the air due to the loss of the Si structure. The current and electric field distributions are similar between AMC-A and AMC-B, which indicates a similar resonant behaviour. Fig. 4Open in figure viewerPowerPoint Current distribution of AMC at 235 GHz (a) Surface current distribution of AMC-A in FSS surface, (b) Surface current distribution of AMC-B in FSS surface, (c) Surface current distribution of AMC-A in ground, (d) Surface current distribution of AMC-B in ground Fig. 5Open in figure viewerPowerPoint Electric field distribution of AMC at 235 GHz (a) Electric field distribution of AMC-A, (b) Electric field distribution of AMC-B Simulated results on the AMC structure are shown in Fig. 6. The reflection loss of AMC-B is <−1.2 dB, which shows the AMC-B for miniaturisation has lower reflection loss than AMC-A, as shown in Fig. 6a. The reflection loss is caused by the loss of the Si substrate. From Fig. 6b, it can be seen that AMC-A exhibits the reflection phase band centred at 237 GHz with a bandwidth of 30 GHz (224–254 GHz). By introducing a miniaturised structure, the AMC-B band shifts to a lower frequency band centred at 235 GHz. The bandwidth of the AMC-B performance is 20 GHz (226–246 GHz). The reduction of total currents causes the loss of the available bandwidth. Hence, there is only resonant frequency shifting of 2 GHz on AMC-B with almost 70% reduction compared with AMC-A. Fig. 6Open in figure viewerPowerPoint Simulated results of AMC structure (a) versus frequency, (b) Reflection phase versus frequency 3 On-chip antenna loading miniaturised AMC 3.1 On-chip double-layer dipole The perspective view of the double-layer dipole is shown in Fig. 7a. The THz on-chip antenna consists of the upper arm on M8, lower arm on M1, via holes from M1 to M8, baluns on M8 and M1, ground on M1 and ground-signal-ground (G-S-G) pad from M1 to M8. A microstrip via-hole balun acts as an unbalance-to-balance transformer from the G-S-G pad to the double-layer dipole. The G-S-G pad is required for probes' measurement. The simulation port is the defined lumped port in HFSS, as shown in Fig. 7c. The optimised dimensions of the proposed antenna are shown in Table 2. Fig. 7Open in figure viewerPowerPoint Geometry of double-layer dipole (a) 3D view of the double-layer dipole, (b) Dimensional details of the double-layer dipole, (c) Definition of excited port in HFSS Table 2. Parameters of double-layer dipole, μm Parameters Values Parameters Values l 400 15 125 250 195 14 37.5 28 10 82 20 114 20 40 The two arms of the double-layer dipole are difference dimensions (, , , ), which connected by a pair of via holes. The length of the dipole is calculated by using the following equation [[17]]: (4) where l is the length of the dipole arm. The double-layer dipole for increasing the operating bandwidth is due to the multi-resonance dipole configuration and the fundamental frequency band. The lengths of baluns are all approximately a quarter-wavelength. The ground plane of the balun and the lower arm of the double-layer dipole are on M1. Due to the phase difference between the top strip and ground plane of the balun, feed point 2 of the dipole arm is phase difference with the other feed point 1. A via-hole permits feed point 2 of a dipole arm to have the same phase as feed point 1 of the other dipole arm. Fig. 8 shows the simulated surface current density vectors on the top metal plane (M8) and bottom metal plane (M1) of the double-layer dipole and balun at 235 GHz. Surface current density vectors also show the balanced current distribution on the double-layer dipole arms. This shows the function of the balun. Fig. 8Open in figure viewerPowerPoint Surface current density vectors of double-layer dipole at 235 GHz (a) Upper arm of double-layer dipole and upper microstrip line of balun (M8), (b) Lower arm of double-layer dipole and ground of microstrip balun (M1) The simulation bandwidth of the double-layer dipole is 40 GHz (228–266 GHz) under the condition of < −10 dB, as shown in Fig. 9a. The double-layer dipole is designed to enhance the 8 GHz bandwidth than a conventional dipole. The peak gain of the proposed antenna is 2.9 dBi at 235 GHz, as shown in Fig. 9b. However, the beam direction is the negative z direction. Fig. 9Open in figure viewerPowerPoint Simulated performance of on-chip double-layer dipole (a) versus frequency, (b) Gain at 235 GHz 3.2 On-chip antenna loading miniaturised AMC plane Due to the small remaining space in the antenna, miniaturised AMC unit-cells are used in double-layer dipole for more stable reflection performance. AMC unit-cells are loaded on M1 and simulated together, as shown in Fig. 10a. Fig. 10b shows a comparison of performance among double-layer dipole, double-layer dipole loading AMC-A and double-layer dipole loading AMC-B, respectively. The bandwidth of double-layer dipole loading AMC-B increases 29 GHz than that loading AMC-B. The resonant frequency of double-layer dipole loading AMC-B offset down 8 GHz bandwidth than that loading AMC-A. Fig. 10Open in figure viewerPowerPoint Simulated performance of double-layer dipole loading AMC-B (a) 3D view of on-chip antenna integration miniature AMC structure, (b) Comparison of versus frequency, (c) Comparison of gain versus frequency For the purpose of gain comparisons, double-layer dipole loading ground plane under silicon substrate is also simulated at the same dimensions. Fig. 10c shows a comparison of gain among double-layer dipole loading ground plane, loading AMC-A, loading AMC-B. It can be seen that the double-layer dipole loading AMC can reduce the undesired backside radiation more efficiently than that loading ground. The gain of double-layer dipole loading AMC-B has been enhanced 1 dB compared with that loading AMC-A in the same areas. The double-layer antenna loading AMC-B shows an almost constant gain of about 0 dBi from 227 to 245 GHz in the broadside direction. The E-field distributions of double-layer dipole without AMC, loading AMC-A and AMC-B are shown in Fig. 11. We can see that the E-field is concentrated at the bottom of the antenna due to the high dielectric constant of the Si substrate, as shown in Fig. 11a. This E-field distribution explains the direction of radiation pattern downward in the on-chip double-layer dipole. Figs. 11b and c show a much smaller fraction of the E-field distributed on the Si substrate when the AMC layers are inserted. It implies the less energy is stored inside the radiation resonator and hence a lower Q, wider bandwidth, and high gain are being achieved. Comparing Figs. 11b and c, the E-field on the Si substrate of the double-layer dipole loading AMC-B is less than that loading AMC-A. Therefore, the bandwidth and gain of antenna loading AMC-B are better. Fig. 11Open in figure viewerPowerPoint E-field distribution at 235 GHz (a) Double-layer dipole without AMC, (b) Double-layer dipole loading AMC-A, (c) Double-layer dipole loading AMC-B 4 Results and discussion The on-chip double-layer dipole with AMC-B is fabricated in the 65 nm CMOS process and its chip photo are shown in Fig. 12. The size of the proposed antenna is . The of the proposed antenna is measured in 220–325 and 140–220 GHz, respectively. The fabricated on-chip antenna is measured based on the Cascade Microtech Elite-300 probe station and Keysight PNA-X (N5247A) with the VDI extender providing the signal source from 140–220 and 220–325 GHz. A G-S-G radio frequency probe with a pitch of is touched on the ground coplanar waveguide line of the proposed antenna for measurement. The loss of the G-S-G probe and cable is <4.887 dB from 200 to 300 GHz. The line-reflect-reflect-match calibration method is adopted on an impedance standard substrate. The simulation bandwidth is 60 GHz (223–283 GHz) under the condition of < −10 dB. The measurement bandwidth is 81 GHz (200–281 GHz) under the condition of < −10 dB, as shown in Fig. 12c. The measurement bandwidth shows good correspondence with the simulation results. At lower frequency below 222 GHz, the depth of measurement is deeper than in the simulation results. Above 200 GHz, the insertion loss is relatively high compared with the simulation results because of the error in the conductivity of copper, loss tangent of inter level film and loss of the measured G-S-G probe and cable. Radiation pattern measurement facilities are shown in Fig. 12b. The simulated gain of the proposed antenna is 0 dBi at 235 GHz, as shown in Fig. 12d. Due to the limitation of the measurement dynamic range at 200–325 GHz, the received signal is under noise floor of the measurement system and thus cannot be detected. Adding amplifiers to the measurement system would improve the dynamic range of the measurement, but the commercially available amplifiers at 235 GHz are hard to be found in the market at this stage. Fig. 12Open in figure viewerPowerPoint Measured results and radiation gain of the double-layer dipole loaded AMC-B structure (a) Fabricated prototype, (b) Radiation pattern measurement facilities, (c) Simulated and measured result of double-layer dipole with AMC-B structure, (d) Simulated gain of double-layer dipole with AMC-B structure at 235 GHz The parameters of the proposed antenna and other CMOS THz antennas are listed in Table 3. The proposed antenna loading the miniaturised AMC has successfully achieved wideband bandwidth, high gain, and high efficiency. Table 3. Key data of several CMOS THz antenna designs This work [[5]] [[8]] [[4]] process 65 nm 45 nm 130 nm 65 nm dimension, μm2 250 × 410 200 × 200 500 × 600 410 × 410 frequency range, GHz 81 (200–281) (mea.) 410 (sim.) 434 (sim.) 32.6 (251–283.6) (sim.) gain, dBi 0 (sim.) 1.1 (sim.) 0.55 (sim.) −0.5 (sim.) efficiency, % 63 (sim.) 22 (sim.) 49.8 (sim.) 21.4 (sim.) 5 Conclusion A 235 GHz on-chip antenna with miniaturised AMC loading in 65 nm CMOS is demonstrated in this study. The double-layer dipole is designed to enhance impedance bandwidth and the miniaturised AMC is integrated into the on-chip antenna to increase peak gain. The on-chip antenna is fabricated in a die area of . The measurement bandwidth is 81 GHz (200–281 GHz) under the condition of < −10 dB. The gain of the antenna is up to 0 dBi gain at 235 GHz. The measurement results are in good agreement with the simulation results. 6 Acknowledgments This work is supported by the project 61372036 and 61601050 from the National Natural Science Foundation of China (NSFC), the project of 6140518040116DZ02001. The authors appreciate fabrication and the measurement support from Nanyang Technological University, Singapore. 7 References [1]Sengupta, K., Hajimiri, A.: 'A 0.28 THz power-generation and beam-steering array in CMOS based on distributed active radiators', IEEE J. Solid-State Circuits, 2012, 47, (12), pp. 3013– 3031 [2]Pozar, D.M.: 'Considerations for millimeter wave printed antennas', IEEE Trans. Antennas Propag., 1983, 31, (5), pp. 740– 747 [3]Deng, X.D., Li, Y., Liu, C., et al.: '340 GHz on-chip 3-D antenna with 10 dBi gain and 80% radiation efficiency', IEEE Trans. Terahertz Sci. Technol., 2015, 5, (4), pp. 619– 627 [4]Tajima, T., Song, H.J., Ajito, K., et al.: '300-GHz step-profiled corrugated horn antennas integrated in LTCC', IEEE Trans. Antennas Propag., 2014, 62, (11), pp. 5437– 5444 [5]Seok, E., Shim, D., Mao, C., et al.: 'Progress and challenges towards terahertz CMOS integrated circuits', IEEE J. Solid-State Circuits, 2010, 45, (8), pp. 1554– 1564 [6]Han, R., Zhang, Y., Coquillat, D., et al.: 'A 280-GHz Schottky diode detector in 130-nm digital CMOS', IEEE J. Solid-State Circuits, 2011, 46, (11), pp. 2602– 2612 [7]Chu, H., Guo, Y.X., Lim, T.G., et al.: '135-GHz micromachined on-chip antenna and antenna array', IEEE Trans. Antennas Propag., 2012, 60, (10), pp. 4582– 4588 [8]Hou, D., Xiong, Y.Z., Goh, W.L., et al.: '130-GHz on-chip meander slot antennas with stacked dielectric resonators in standard CMOS technology', IEEE Trans. Antennas Propag., 2012, 60, (9), pp. 4102– 4109 [9]Ou, Y.C., Rebeiz, G.M.: 'On-chip slot-ring and high-gain horn antennas for millimeter-wave wafer-scale silicon systems', IEEE Trans. Microw. Theory Tech., 2011, 59, (8), pp. 1963– 1972 [10]Trentini, G.V.: 'Partially reflecting sheet arrays', IEEE Trans. Antennas Propag., 2003, 4, (4), pp. 666– 671 [11]Chaimool, S., Chung, K.L., Akkaraekthalin, P.: 'Bandwidth and gain enhancement of microstrip patch antennas using reflective metasurface', IEEE Trans. Commun., 2013, 93-B, (10), pp. 2496– 2503 [12]Hadarig, R.C., De Cos, M.E., Lvarez, Y.A., et al.: 'Novel bow-tie antenna on artificial magnetic conductor for 5.8 GHz radio frequency identification tags usable with metallic objects', IET Microw. Antennas Propag., 2011, 5, (9), pp. 1097– 1102 [13]Agarwal, K., Nasimuddin, AlphonesA.: 'Unidirectional wideband circularly polarised aperture antennas backed with artificial magnetic conductor reflectors', IET Microw. Antennas Propag., 2013, 7, (5), pp. 338– 346 [14]Hadarig, R.C., de Cos, M.E., Las-Heras, F.: 'Novel miniaturized artificial magnetic conductor', IEEE Antennas Wirel. Propag. Lett., 2013, 12, pp. 174– 177 [15]Bao, X.Y., Guo, Y.X., Xiong, Y.Z.: '60-GHz AMC-based circularly polarized on-chip antenna using standard 0.18-µm CMOS technology', IEEE Trans. Antennas Propag., 2012, 60, (5), pp. 2234– 2241 [16]Lamminen, A.E.I., Vimpari, A.R., Saily, J.: 'UC-EBG on LTCC for 60-GHz frequency band antenna applications', IEEE Trans. Antennas Propag., 2009, 57, (10), pp. 2904– 2912 [17]Gao, F., Zhang, F., Lu, L., et al.: 'Low-profile dipole antenna with enhanced impedance and gain performance for wideband wireless applications', IEEE Antennas Wirel. Propag. Lett., 2013, 12, pp. 372– 375 Citing Literature Volume12, Issue5April 2018Pages 727-733 FiguresReferencesRelatedInformation