| As the widely using of handset,there is a higher requirement of the size and the about the performance important RF part-handset antenna.Because there are small space and complex environment in the handset,so many researchers dedicate to research the methods that improving the techniques to make the antennas' miniaturization and multi-band.With the GSM900/DCS 1800 dual-band handsets,users can change the communication band between GSM and DCS freely,so it is used widely.As the crucial part of the dual-band handset,the research on the dual-band antenna is useful.With the development of the wireless communications,the communication service providers and the communication equipment manufacturers call for the tools that radiate little energy and effect far distance.It makes the available signal to be on a very low level in most environments.So it is worth to research the low noise amplifier which can enlarge the available signal while avoiding make the SNR being worse.Based on widely reference of domestic and overseas literatures and the handset internal antenna theory,the PIFA antenna is analyzed exhaustively.A PIFA antenna for GSM900MHz/DCS1800MHz handset is designed.In this design,the electromagnetic simulation software HFSS was used to simulate and optimize the antenna,on the basis of the optimization result,the antenna was manufactured and tested.The test result show that the frequency range of the dual-band antenna is:880MHz-960MHz for GSM, and 1710MHz-1880MHz for DCS which is meeting to the design requirement.In this paper,a LNA worked at frequency 1800MHz is also designed.Based on the principle and analysis methods of LNA,the initial design was introduced.Then the circuit parameters were optimized with the electromagnetic simulation software ADS.Finally the LNA was manufactured and tested.The simulation and test result show that at the frequency 1800MHZ,the noise figure is 1.387,the input return loss is -9.40dB and the gain is 9.44dB which is fit the design requirement. |
PDF Full Text Request