Tunable Patch Antenna Printed on a Biased Nematic Liquid Crystal Cell

Radiation Pattern Reconfigurable Waveguide Slot Array Antenna Using Liquid Crystal

“…Compared with ferroelectric crystals (e.g., (Ba,Sr)TiO 3 ), the nematic LC has a lower bias voltage, which makes it more suitable for portable reconfigurable electromagnetic wave device design [11][12][13][14]. In recent years, nematic LCs have been widely applied for tunable filters [15][16][17][18], for tunable phase shifters [19][20][21], for active metamaterials [22][23][24][25], and for frequency [26][27][28], polarization [21,29], or radiation pattern reconfigurable [30][31][32][33][34][35] antennas. Phase shifts of LC phase shifters are usually about 150°and 300°in the microwave [7] and millimetre-wave [36,37] bands, respectively.…”

A Novel Tunable Microstrip Patch Antenna Using Liquid Crystal

“…In this context, tunable antennas have been studied intensively [1][2][3][4][5][6][7][8][9][10][11][12]. A key factor in designing tunable antennas is the technology used for realizing the tunability.…”

“…A key factor in designing tunable antennas is the technology used for realizing the tunability. The available technologies include radio frequency microelectromechanical systems (RF-MEMS) [1,2], semiconductor solutions [3,4] and tunable dielectrics such as ferroelectric [5,6] and liquid crystal (LC) [7][8][9][10][11][12]. Among them, the LC technology is a promising one, because the dielectric loss of LC decreases with increasing frequency, and the manufacturing technology is mature [13].…”

“…Tunable antennas using LC are usually designed in a microstrip patch antenna structure [9][10][11][12]. The microstrip patch antenna structure has two layers of substrates and one layer of superstrate.…”

Frequency-Agile, Efficient, Circularly Polarized, Near-Field Resonant Antenna: Designs and Measurements

“…These technologies have been employed successfully in various antenna designs, such as patch antennas [12][13][14][15][16], slot antennas [17,18], dielectric resonator antennas [19], dipole antennas [20], loop antennas [21], PIFAs [22], compact arrays [23], and different versions of electrically small antennas [24][25][26][27][28][29][30]. To the best of our knowledge, numerous efforts (e.g., [11]- [30]) have previously been focused on enlarging the effective impedance bandwidth of linearly polarized (LP) antennas.…”