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Comparison of Spiral and Metamaterial Inspired Patch Antenna for 4G LTE Applications
Published in Amit Kumar Tyagi, Ajith Abraham, A. Kaklauskas, N. Sreenath, Gillala Rekha, Shaveta Malik, Security and Privacy-Preserving Techniques in Wireless Robotics, 2022
Tushar P. Dave, Nita T. Dave, Jagdish M. Rathod
Spiral antenna is useful to obtain gain and wide LTE band response. The disadvantage of spiral antenna is high impedance, big size and non-planar structure when uses balun for impedance matching. Here we proposed square spiral antenna whose impedance is 50Ω. The size of proposed square spiral antenna is 150mm×150mm (refer figure 5.3). The square spiral shape is placed by decreasing the width of metal line gradually till end is reached. This can be observed from the Table 5.2 showing the dimensions of antenna. Balun is not required for impedance matching. The current flows through the square path and width of square path reduces along the length. When the current enters the S11 starts decaying and may go below -10dB. When the current experiences the discontinuities at the edges of different width it returns up and then while travelling in new width line again it decays. So eventually the S11 graphof such spiral antenna would be either cover broad band of LTE spectrum or as in proposed design having multiple narrow LTE bands. Narrow band results are more suitable to communication antennas to avoid adjacent signal interference.
EMI and EMC Test Methods
Published in John G. Webster, Halit Eren, Measurement, Instrumentation, and Sensors Handbook, 2017
Tuned dipole, biconical, and log-periodic antennas are linearly polarized antennas because they respond to only one polarization component of a propagating wave. If the antenna is oriented horizontally, only the horizontally polarized component of the wave will affect it. Similarly, only the vertically polarized component will affect a vertically oriented antenna. Thus, with two measurements, any linearly polarized antenna will detect any type of field polarization. Other types of antennas, such as the spiral antenna, are designed to detect a circularly polarized wave. They will detect vertically and horizontally polarized waves, but they could miss a wave that is circularly polarized in the reverse direction (e.g., counterclockwise instead of clockwise). Consequently, circularly polarized antennas are forbidden for many types of field measurements.
Ultra-Wideband Antenna Technology
Published in James D. Taylor, Introduction to Ultra-Wideband Radar Systems, 2020
P. R. Foster, J. Doss Halsey, Malek G. M. Hussain
A spiral antenna is a frequency-independent antenna.32 In its basic form, it consists of two interleaved arms wound in a spiral, each terminated in a resistance. The feed (a balance-to-unbalance transformer is required) is at the center and radiation occurs from the points on the spiral which have a half wavelength in transmission line between them. Higher frequencies radiate from regions near the central feed point and lower frequencies from the edges.
Development of a fully planar logarithmic spiral antenna with integrated balun in UWB GPR systems for landmines detection
Published in Electromagnetics, 2022
Narek Grigoor-Feghi, Reza Masoumi, Robab Kazemi
Antenna is a key element of any GPR system. Currently, the antennas, which have been used in GPR systems include horn (Ahmed et al. 2015), bow-tie (Serhir and Lesselier 2018), logarithmic spiral (He and Akizuki 2010; Kazemi 2018; Richardson et al. 2020), slot spiral (Patnaik, Arunachalam, and Krishnamurthy 2016), conical spiral (Yao, Liu, and Georgakopoulos 2017), and Vivaldi (Takach et al. 2016) antennas. In general, it has been shown that logarithmic spiral antenna is often a good candidate for detection systems due to its planar structure and frequency-independent performance. Furthermore, the spiral antenna radiates circularly polarized waves, which is a major advantage over linearly polarized antennas. However, the high input characteristic impedance and the need for balanced feeding structure are the challenges in practical implementation of spiral antennas. A balun is required to transform the signals from an unbalanced feed line (e.g., coaxial cable) to a balanced spiral arm. In recent years, a number of wideband baluns, such as a tapered microstrip to a parallel strip line (Chen et al. 2020; Chen, Zhang, and Xu 2020; Jastram and Filipovic 2018; Sakomura et al. 2018; Singh and Deshpande 2017), coplanar waveguide to coplanar stripline balun (Thaysen, Jakobsen, and Appel Hansen 2000; Tilley, Wu, and Chang 1994), and Vivaldi-shaped balun (Yoo et al. 2019) have been reported. However, most of the configurations are vertically connected to the antenna, which makes the antenna bulky and frail or have limited bandwidth.
Design of a cavity-backed spiral antenna using frequency-dependent impedance of a stepped-width arm for low frequency gain enhancement
Published in Electromagnetics, 2020
Spiral antennas have been widely utilized in a variety of commercial and military applications such as mobile communications, Global Positioning Systems (GPSs), and electronic warfare (EW) due to their broadband nature of impedance matching and circularly polarized patterns (Buck and Filipovic 2018; Guinvarc’h and Haupt 2010; Saenz et al. 2014). One of the recent research topics regarding the spiral antenna is to derive the required array characteristics by using a large number of antennas in a given space; consequently, the miniaturization of the spiral antenna is a key technology for implementing such systems (Nakano, Sataki, and Yamauchi 2010), (Nakano et al. 2009). However, since the lowest operating frequency is determined theoretically by the outer radius of the spiral arm, the gain in performance at the low operating frequency is degraded when the antenna configuration is miniaturized (Fu et al. 2010), (Ghassemi et al. 2011). Therefore, a significant amount of effort has been made to enhance the low-frequency gain while increasing the antenna bandwidth. Numerous studies, particularly on improving the bandwidth of the spiral antennas, have already focused on optimizing the shape and number of spiral arms. For example, techniques such as adjusting the turn number, width and rotation angle of the spiral arms (Nakano et al. 2008), tapering the edge shape of the arm (Chen and Huff 2011), varying the center position of the arm that is connected to the feed (Nakano et al. 2011), and inserting additional lumped elements in the arm (Lee et al. 2011), have been reported so far.
Design and Development of Cavity-Backed Reconfigurable Square Spiral Antenna
Published in IETE Journal of Research, 2019
D. Rama Krishna, V. M. Pandharipande
Spiral antennas belong to a class of aperture antennas called the frequency independent antennas. Since the introduction of the spiral antenna by Rumsey in 1950s [1], the spiral antenna geometry has been the subject of investigations for several years [1–6]. The main characteristics of the spiral antenna are consistent gain, input impedance over wide bandwidths, wide half power beam width (HPBW) and circular polarization (CP) for the radiated field [1–3]. These characteristics are highly compatible with wireless systems such as wireless-LAN, GSM, CDMA, aerospace, and Electronic Warfare (EW) applications [4–6]. The spiral antenna has a bi-directional radiation pattern. However, the practical applications demand unidirectional radiation which is achieved in the present case by mounting the spiral element onto the aperture of a cylindrical metallic cavity.