Directionally controlled antennas are applicable in many mobile telecom markets and will find their way into aircraft, ships, automobiles, other transport vehicles and consumer products. Advanced, smart antennas generating or receiving directionally controlled radiation beams are based on multiple antenna array elements combined with appropriate signal processing. To obtain an optimal radiation distribution, the signals received by / transmitted from the antenna array must be time compensated with respect to the wave front. Presently used electronic phase shifting devices show a strong frequency dependence. Processing of wide frequency bands for high quality broadband communication is thereby extremely difficult. This problem can be solved by developing new time shifting devices (which are frequency independent) based on very accurate True Time Delay circuits. Because of these high accuracy, the large bandwidth and high frequency handling capacity, True Time Delay circuits will be based on newly developed micro-optical technology.
The advantages of smart antennas are tremendously:
- more efficient use of transmission energy is beneficial for the battery lifetime of mobile devices;
- there is an increase of range coverage, decrease of transmitted power and noise sensitivity;
- increase in capacity, both bits/s or bandwidth (spectrum efficiency) and users per sector;
- increase in quality of service;
- availability of the user’s position.
The scope of the SMART project is the research and development of an integrated radiation control technology based on a new dimension in antennas for mobile systems, being “space” (directional sensitivity), providing mobile wireless broadband data communication access with low radiation impact.
The development of a conformal aircraft array antenna will serve as a pilot application. Some of the most difficult technical problems which have to be solved are:
- novel broadband (2 GHz) antenna concepts based on new conformal multilayer substrate compositions and stacked antenna radiation patterns;
- photonic broadband signal processing based on novel ring resonator principles achieving True Time Delays of 0–5 ns with 1 picosecond accuracy;
- spatial equalization algorithms for multi antenna signal processing;
An interesting application area is aviation, caused by the customer’s demand for availability of broadband internet and other multimedia applications, live in the sky. Conformal array antennas will be used for broadband satellite communication. Novel conformal antenna developments in combination with photonics control will be investigated and developed in order to create this demonstrator.
Arjan Meijerink, "SMart Antenna systems for Radio Transceivers (SMART)," TE Presentation, May 27 2008. PPT slides see below.