| Seeker conformal array has received much attention in recent years, because it has many advantages such as remaining more space for other devices on seeker, steady structure and so on. Compared with other kinds of antennas, coplanar antenna can easily realize conformal array. Various antennas fed by coplanar waveguide have been developed recently because coplanar waveguide has numerous advantages compared with microstrip line such as lower radiation leakage, less dispersion and easier to be connecting with active and passive components. So it is a good choice for seeker conformal array using elements fed by coplanar waveguide.In Chapter One, the development and present situation of the seeker conformal array are introduced firstly, and the analysis and prediction of the trends of seeker conformal array are also given. Then the main content and innovation of this paper are described briefly.In Chapter Two, the basic theory of microstrip patch antennas and the basic characteristics of coplanar waveguide transmission line are introduced briefly. Then analysis of the transmission characteristics of coplanar waveguide corner and a design of modified coplanar waveguide corner are given. The transmission characteristics of the coplanar waveguide with corner are improved evidently. The development and present situation of coplanar waveguide slot antennas are introduced briefly afterwards. A frequency reconfigurable coplanar waveguide folded-slot antenna is designed. It can operate at different frequency bands by controlling the states of switches on the antenna, its return loss is better than -10dB from 2.70GHz to 5.24GHz, and the combined bandwidth is 2.54GHz (63%). Finally, the present situation of coplanar waveguide patch antennas is introduced briefly, and a small size coplanar waveguide back fed patch antenna is designed. By laying the patch on the low dielectric constant material with thicker thickness while remaining the circuitry on the high dielectric constant material with thinner thickness, compact size and good performance are obtained. By loading slots on the patch, nearly 50% area is reduced compared with conventional patch.In Chapter Three, the basic theory of power divider is introduced firstly. Then the present situation of coplanar waveguide power dividers is introduced briefly. A coplanar waveguide power divider operating at X band is designed, which has a bandwidth of 26.5% (8.71 GHz~11.37 GHz), an insertion less than 0.48 dB, and its isolation, return losses of input port and output port are less than -20dB.In Chapter Four, the main content and innovation of this paper are summarized. |
