A novel two-iteration binary tree fractal bionic structure antenna is proposed for the third generation (3G), fourth generation (4G), WLAN, and Bluetooth wireless applications in the paper, which is based on the principles of conventional microstrip monopole antenna and resonant coupling technique, combined with the advantages of fractal geometry. A new fractal structure was presented for antenna radiator, similar to the tree in nature. The proposed antenna adapted two iterations on a fractal structure radiator, which covers mobile applications in two broad frequency bands with a bandwidth of 44.2% (1.85–2.9 GHz) for TD-SCDMA, WCDMA, CDMA2000, LTE33-41, and Bluetooth frequency bands, and 11.5% (4.9–5.5 GHz) for WLAN frequency band. The proposed antenna was fabricated on a G10/FR4 substrate with a dielectric constant of 4.4 and a size of 50 × 40 mm2. The good agreement between the measurement results and the simulation results validate that the proposed design approach meet the requirements for various wireless applications.

This study proposes a novel square-circle structure fractal multibroadband planar antenna, similar to an ancient Chinese coin-like structure, for second generation (2G), third generation (3G), fourth generation (4G), WLAN, and navigation wireless applications. The device is based on the principles and structural features of conventional monopole antenna elements, combined with the advantages of microstrip antennas and fractal geometry. A fractal method was presented for circular nested square slotted structures, similar to an ancient Chinese copper coin. The proposed antenna adapted five iterations on a fractal structure radiator, which covers more than ten mobile applications in three broad frequency bands with a bandwidth of 70% (1.43-2.97 GHz) for DCS1800, TD-SCDMA, WCDMA, CDMA2000, LTE33-41, Bluetooth, GPS (Global Positioning System), BDS (BeiDou Navigation Satellite System), GLONSS (Global Navigation Satellite System), GALILEO (Galileo Satellite Navigation System), and WLAN frequency bands, 16.32% (3.32-3.91 GHz) for LTE42, LTE43, and WiMAX frequency bands, and 10.92% (4.85-5.41 GHz) for WLAN frequency band. The proposed antenna was fabricated on a 1.6 mm thick G10/FR4 substrate with a dielectric constant of 4.4 and a size of 88.5 × 60 mm 2 . The measurement results reveal that the omnidirectional radiation patterns achieve a gain of 1.16-3.75 dBi and an efficiency of 40-72%. The good agreement between the measurement results and simulation validates the proposed design approach and satisfies the requirements for various wireless applications.

A novel Koch Snowflake and Sierpinski Carpet combined fractal multiband antenna is proposed for 2G/3G/4G/5G/WLAN/Navigation wireless applications in the paper, which is based on the principles of conventional microstrip monopole antenna and resonant coupling technique, combined with the advantages of fractal geometry. The antenna has the combination radiator of a two iteration Koch snowflake fractal with a four iteration Sierpinski Carpet fractal slotted inside, and a six edges ring resonator on back side to generate six resonant frequencies. The antenna covers more than ten mobile applications in six frequency bands with a bandwidth of 12.2% (0.85–0.96 GHz) for GSM900 and CDMA2000, 23.2% (1.22–1.54 GHz) for TD‐LTE (B‐TrunC), 13.1% (1.86–2.12 GHz) for LTE33‐37 and TD‐SCDMA, 29.9% (2.4–3.22 GHz) for ISM2.4G, Bluetooth, GPS, COMPASS, GLONSS, GALILEO, WLAN, 7.3% (3.69–3.97 GHz) for LTE42/43 and WiMAX, 21.1% (4.84–5.98 GHz) for WLAN and 5G systems. The proposed antenna is fabricated on FR4 substrate, the size is 80*54*1.6 mm3. The measured results reveal that the omnidirectional radiation patterns with −2.9 to 4.64 dBi gain. The good agreement between the measurement results and the simulation results validate that the proposed design approach meet the requirements for various wireless applications.

This work proposes a novel multiband slotted planar antenna with a “回” structure, which is similar to an ancient Chinese window grille structure. The antenna is suitable for wireless applications, including the second-generation (2G), third-generation (3G), fourth-generation (4G), and fifth-generation (5G) technologies, as well as WLAN and navigation applications. The proposed antenna is based on the structural characteristics of a conventional monopole antenna, which combines the advantages of a slit structure and microstrip line structure for feeding. It adopts a circular patch with a slit structure placed in it, which is similar to the Chinese classical pane structure. This structure enables an effective reduction of the size of the antenna. The four-sided “回” gaps change the path of current flow and are coupled to each other, improving the impedance matching and radiation characteristics of the entire target frequency band. The antenna covers the frequency ranges of 1.58–1.77 GHz (12%), 2.1–2.50 GHz (17%), 3.61–4.09 GHz (12%), and 4.75–6.5 GHz (36%), permitting more than 10 wireless applications in these 4 frequency bands. This antenna uses an FR-4 dielectric material; the relative dielectric constant of the dielectric plate is 4.4, and the actual dimensions of the antenna are 85 × 70 × 1.6 mm³. The test and simulation results are in good agreement with each other, thus confirming that the proposed design method meets the requirements of various wireless applications.

This study proposes a multiband printed planar antenna with cloud-like grooves. The outer contour of the antenna is shaped like a cloud, and the groove-like pattern is similar to the cloud-like pattern in ancient China. It can support 3G, 4G, 5G, WLAN, Bluetooth, WiMAX, and other applications. Based on the traditional monopole antenna, the antenna combines the advantages of a coplanar waveguide. The antenna uses an Archimedes helix to create grooves that resemble ancient Chinese cloud structures. Three effective frequency bands are obtained. The relative bandwidth of the first frequency band (1.8–2.6 GHz) is 32.7%, covering 5G band n2 (1.85 GHz–1.99 GHz), WCDMA (1.9–2.17 GHz), LTE33-41 (1.9–2.69 GHz), Bluetooth (2.4–2.48 GHz), WLAN (2.4–2.48 GHz), LTE Band40 (2.3–2.4 GHz), ISM Band (2.42–2.4835 GHz), WiMAX (2.3 GHz), and SCDMA (1.88–2.025 GHz and 2.3–2.4 GHz). The second frequency band (3.35–4.1 GHz) has a relative bandwidth of 20.5%, covering LTE42/43 (3.4–3.8 GHz) and 5G band n78 (3.4 GHz–3.8 GHz). The relative bandwidth of the third band (5.5–7.9 GHz) is 40.3%, covering Emergency and Public Protection (5.85 GHz–5.925 GHz) (WRC03). The antenna is printed on a G10/FR4 dielectric board with a size of 1.6 ∗ 45 ∗ 40   m m 3 , the dielectric constant is 4.4, and the omnidirectional radiation pattern gain is 0.59–4.14 dBi. The measurement results are in good agreement with the simulation results. The proposed design method is verified to meet the requirements of various wireless applications.