| In recent years,active phased array radar has received widespread attention due to its uniqueness.It has the characteristics of high output power,long range,high accuracy,high reliability,and has been widely used in military and civil fields,such as airborne,satellite-based,electronic countermeasures,communications,navigation,meteorology and so on.However,with the increasing availability of modern communication technology,the demands of various platforms are becoming more stringent,making it necessary for the design of active phased array radar to meet their performance targets while meeting the design goals of miniaturization,high integration and high reliability.As a core module of active phased array radar,the T/R module not only determines the performance of active phased array radar,but also plays a decisive role in the size of active phased array radar.Therefore,it is important to realize a miniaturized,highly integrated and reliable T/R module design.This research focuses on the miniaturization of X-band T/R module,with the following details:(1)The design of the module circuit schematic is based on the module design indicators,combined with MMIC technology.The layout and wiring of the transceiver link is then carried out according to the overall circuit schematic,rationalizing the placement of the devices to avoid interference and solving the problems of pulse top-down and heat dissipation when the module is in operation.(2)Based on the schematic diagram of the module,Altium Designer and Ansoft HFSS software are used to complete the layout drawing of the LTCC substrate and the simulation and optimization of the signal interconnection structures such as strip lines,coplanar waveguides,coaxial-like and gold wire bonding lines to ensure that the return loss of each port is below-20 d B.The above-mentioned work should be completed by considering the technical difficulties such as ground plane integrity,electromagnetic compatibility and transmission loss and so on.(3)The overall structure of the module is finalized.It uses an 18-layer LTCC substrate structure,including the control signal layer,ground layer,RF signal layer and power layer.After testing,the final module single channel output power is essential above 46 d Bm and the receiving branch gain is greater than 20 d B.The noise factor is less than 2.3 d B.The volume of the entire T/R module is 46.35 mm×59.2 mm×12 mm,with the characteristics of large output power.In order to further reduce the size of the module,a new three-dimensional structure T/R module design idea is proposed.The T/R module utilizes important technical means such as LTCC technology,MMIC technology,BGA,hair button and others at the same time.The module design is realized by two LTCC substrates.The connection of the substrates is realized by BGA in the middle,and the SMP-hair button connector is used as the RF signal input and output structure.And the final size of the upper and lower two LTCC substrates are 27 mm×27 mm×2.2 mm,27 mm×27 mm×0.6mm.Compared to the previous part of the module,the size of the inner cavity is reduced by 37%,featuring a small size.At the same time,combined with the key link simulation parameters,the module output power in the X-band is greater than 46 d Bm.The receiving gain is greater than 20 d B,and the noise factor is less than 2.5 d B.The overall ideal simulation parameter index meets the design requirements,and the overall size of the module is smaller. |
PDF Full Text Request