No abstract

Surrogate models are widely used in antenna design for optimization efficiency improvement. Currently, the targeted antennas often have a small number of design variables and specifications, and the surrogate model training time is short. However, modern antennas become increasingly complex which need much more design variables and specifications, making the training time become a new bottleneck, i.e., in some cases even longer than electromagnetic (EM) simulation time. Therefore, a new method, called training cost reduced surrogate model-assisted hybrid differential evolution for complex antenna optimization (TR-SADEA) is presented in this paper. The key innovations include: (1) A self-adaptive Gaussian Process surrogate modeling method with a significantly reduced training time whilst mostly maintaining the antenna performance prediction accuracy, and (2) A new hybrid surrogate model-assisted antenna optimization framework which reduces the training time and increases the convergence speed. An indoor base station antenna with 2G to 5G cellular bands (45 design variables, 12 specifications) and a 5G outdoor base station antenna (23 design variables, 18 specifications) are used to demonstrate TR-SADEA. Experimental results show that more than 90% of the training time and about 20% iterations (simulations and surrogate modeling) are reduced compared to a state-of-the-art method while obtaining high antenna performance.

No abstract

This paper presents a quadruple-band indoor base station antenna for 2G/3G/4G/5G mobile communications, which covers multiple frequency bands of 0.8-0.96 GHz, 1.7-2.7 GHz, 3.3-3.8 GHz and 4.8-5.8 GHz and has a compact size with its overall dimensions of 204 × 175 × 39 mm 3. The lower frequency bands over 0.8-0.96 GHz and 1.7-2.7 GHz are achieved through the combination of an asymmetrical dipole antenna and parasitic patches. A stepped-impedance feeding structure is used to improve the impedance matching of the dipole antenna over these two frequency bands. Meanwhile, the feeding structure also introduces an extra resonant frequency band of 3.3-3.8 GHz. By adding an additional small T-shaped patch, the higher resonant frequency band at 5 GHz is obtained. The parallel surrogate model-assisted hybrid differential evolution for antenna optimization (PSADEA) is employed to optimize the overall quadruple-band performance. We have fabricated and tested the final optimized antenna whose average gain is about 5.4 dBi at 0.8-0.96 GHz, 8.1 dBi at 1.7-2.7 GHz, 8.5 dBi at 3.3-3.8 GHz and 8.1 dBi at 4.8-5.0 GHz respectively. The proposed antenna has high efficiency and is of low cost and low profile, which makes it an excellent candidate for 2G/3G/4G/5G base station antenna systems. INDEX TERMS 2G/3G/4G/5G, base station antenna, compact antennas, optimization method, quadrupleband antennas.