Dual-band characteristics of annular-ring slot antenna with circular back-patch

Dual-Frequency Dual-Sense Circularly-Polarized Slot Antenna Fed by Microstrip Line

“…Various other slot combinations are reported to obtain compact/broadband circular polarization [4]- [7]. Annular slot antennas are also employed to obtain dual-frequency and multiple frequency operation by a shorted slot [8], or with a circular back-patch [9], or strip-line [10]. Recently, some techniques have been employed to provide dual circularly polarized antennas.…”

Design and Investigation of a Dual-Band Annular Ring Slot Antenna for Aircraft Applications

“…In recent years, many annular ring slot antennas have been developed for dual-frequency operations [1][2][3][4][5][6][7][8][9][10][11][12][13], and several of methods have been used to create antenna with dual-band characteristic. One of the typical methods is to introduce another concentric annular-ring slot [1][2][3][4][5][6].…”

“…However, in order to obtain the dual-band input impedance matching, some other structures should be embedded into the antenna, such as circular photonic bandgap (PBG) structures [3], tree-shaped coupling strip with branches [5] and a cross-slot [6]. There are many other methods to generate dual-band function, such as using triplate feed [7,8], introducing a back-patch [9], utilizing pin diodes [10], changing the compact annular ring slot structure [11][12][13]. All these antennas provide a better impedance match but have some drawbacks of comparatively complex structures [3, 6-8, 10, 13], high profile [7,8], and a large ground plane [9,12].…”

“…There are many other methods to generate dual-band function, such as using triplate feed [7,8], introducing a back-patch [9], utilizing pin diodes [10], changing the compact annular ring slot structure [11][12][13]. All these antennas provide a better impedance match but have some drawbacks of comparatively complex structures [3, 6-8, 10, 13], high profile [7,8], and a large ground plane [9,12]. On the other hand, there are many classic papers introducing the basic analysis methods of the printed and slot antennas [14][15][16][17], and the operation modes analysis using cavity model of annular ring antennas are also introduced [5,7,8,18], which provide a physical insight for understanding the behavior of the antennas.…”

Design of dual‐band annular slot antenna with strip‐loaded approach

“…Several design approaches and implementations have been demonstrated to fulfill the desired dual-band requirements. The slot section, which is the main element delivers the radiation, can be designed in various forms, including with multiple ring slots [1,2], composite patches inserting into the back of the square slot [3], annular conjunct with a circular back-patch [4] or a slit back-patch [5], an E-like feeding structure with added matching stub at the slot edge and four floating patches on the back [6], and a pair of symmetrical Y-shape-like slots [7]. Furthermore, a design presented elsewhere [8] indicates that the dual-band operation is based on an open-circuited stub at the mid point of the side of the loop opposite to the input of the CPW and the input T-mating circuit is also to match the return loss of the antenna in the desired bands.…”