Multimode and Advanced Terminal Antennas
This chapter introduces multimode antennas for an integrated GNSS receiver, covering the GPS, GLONASS, Compass and Galileo systems. It presents several kinds of multimode GNSS antennas, including microstrip and helix antennas. For each one, some practical and novel designs are presented, such as multi-layer microstrip antennas, slotted-patch antennas, quadrifilar helix antennas, and so on. Finally, the chapter touches on high-precision terminal antennas for differential GPS, including phase centre determination and stability.
5.1 Multiband Terminal Antennas
With the development of satellite navigation technology, many countries have started to build their own satellite navigation systems. Nowadays, these systems are used intensively. The American GPS and the Russian GLONASS are already operating worldwide. The Chinese Compass system has also provided a partial service. Future satellite navigation receivers will provide multimode operation utilising different satellite navigation systems to improve their positioning accuracy and reliability, so the design of terminal antennas for multimode satellite navigation systems is practically desirable.
A multimode satellite navigation receiver is required to cover several frequency bands for the GPS, GLONASS, Galileo and Compass systems, as detailed in Table 1.1. Each GNSS has several frequency bands. The challenges in the design of a multiband receiver antenna come from two requirements: ...