Optimal Design Of Smart Watch Antennas And Indoor Base Station Antennas

With the rapid development of electronic communication technology and medical industry,smart electronic devices combining biological medical functions are coming into being.Smart watch antenna and smart indoor base station antenna are playing an increasingly important role in mobile communication.Four smart array antennas are designed in this paper,and their main work includes:1.Firstly,an eight-element smart array antenna operating at Bluetooth/WiFi band is designed for smartwatches.The array antenna is composed of eight planar inverted-F antennas（PIFA）,and the eight PIFA elements are evenly spaced on four sides of the substrate.The antenna model is optimized by using HFSS15.0 simulation software and the optimal excitation is optimized by using the method of maximum power transmission efficiency.In the feed part,An RF feeding circuit has been designed to realize the optimized distributions obtained from MMPTE,and the input signal is equally divided into 8 outputs.Finally,a real object is processed for testing,and the test results are compared with the experimental results.The experimental results show that the array antenna can achieve the function of beam scanning.2.In view of the low gain of the eight-element PIFA array antenna mentioned above,a four-element planar meander dipole smart antenna operating at Bluetooth/WiFi band is designed in this paper,which is also applied to smartwatches.Due to space constraints,we have to bend the planar dipole.The optimal excitation is optimized by using the method of maximum power transmission efficiency,so as to obtain the optimal gain of the array.In the feed section,we add a matching load to any four ports of an eight-minute RF feed circuit,and use the remaining four ports to provide the optimal excitation calculated for the array antenna.The experimental results show that the design can achieve beam scanning with good directional on the vertical.Compared with the eight-element PIFA array antenna,the gain of this array antenna is improved obviously.3.Finally,we designed two low profile smart array antennas for indoor base stations.In this paper,two dual-mode low-profile smart antenna arrays operating at 2.45 GHz are designed.To make full use of the substrate,a circular planar dipole is selected as the element of the array antenna,and a ring reflector is introduced into the antenna to adjust the directional gain.The first array antenna is composed of four planar arc-shaped dipoles and a reflection ring,and the optimal excitation required by the antenna array is optimized by the same method,so as to obtain the optimal gain and before-and-after ratio of the array.The experimental results show that the design can switch between omnidirectional mode and directional mode,and can achieve the beam pointing at different angles.In order to obtain higher omnidirectional gain and maintain more uniform gain in horizontal plane of directional mode,we propose a second design,which uses the first design as antenna subarray,which uses the first design as the antenna sub array.Two sub arrays are used to form an 8-element antenna array,separated by a foam layer and placed coaxially with one rotated 45 degrees around the center axis and the height of the antenna is 0.40λ₀.The experimental results show that the designed omnidirectional gain is improved and more uniform gain is maintained in the horizontal plane of the directional mode.