Homepage of Jasper Velner
PhD. students ( / AIO )
|Name||J. Velner, MSc (Jasper)|
|Department||EEMCS / Electrical Engineering|
|P.O. Box 217|
|7500 AE Enschede|
|Phone||+31 53 489 4831|
|Secretary||+31 53 489 2644|
Next Generation of Phased Array Transmitter Electronics
Phased array systems have traditionally been developed for military purposes, where they provide an electronic alternative for slow and bulky mechanical antenna systems. The concept of phased array is to use constructive and deconstructive interference from an array of antenna elements to create a radiation pattern that can, to a high degree, be pointed in any desired direction. The concept also works in reverse on the receive side, where incident waves reach different array elements at different times, depending on the angle at which they arrive. This fact can be used to make an array that has a high spatial selectivity, which is extremely useful when a weak signal is to be received in the presence of unwanted interferers.
The beam steering is accomplished by adding a time delay taper, or in the case of a narrow band signal a phase shift taper, to the signal that goes to, or comes from, the different array elements. The building blocks required for this suffer from limitations such as low bandwidth and non linear transfer functions. Also, the present day systems generally feature one common input source for a large number of elements and operate only in a single frequency band (determined by the common input source).
The aim of this research is to develop a more modular transmission system, integrated on a single chip, that can fully control a small array of elements and can function over a wide band of frequencies. Many such chips can be combined to control a large array, or they can have different inputs to divide the array into smaller sub arrays, each with their own distinct function. On these chips, the aim is to do as much as possible in the digital domain to provide a high degree of flexibility. Finally, a way to solve or circumvent the problems caused by the non-idealities in the delay or phase shift elements is an important aspect of this research. All this will hopefully serve to create the building blocks for a cheaper, more flexible phased array transmission system.