Control Driver Designing and Programming for Very Large Order RF-MEMS Switch Matrices(2)
systems, MEMS technology has many advantages such as lower power consumption,
lower cost, smaller size, higher precision and increased reliability. Among the
advantages of MEMS technology, the most attractive one would be their ability to
communicate with electrical elements in semiconductor chips easily [1].
For telecommunication systems in space very large order switching matrices are
needed, where a great number of inputs are connected with the corresponding outputs.
Requirements for such a switching matrix are low insertion loss, high isolation with low
coupling between the various transmission channels, low power consumption and a
symmetrical transmission behavior. RF-MEMS represent an attractive technology for
satellite applications thanks to their low insertion loss in the transmission path, low
power consumption, compact size and weight and high integrality [2][3] [4][5][6][7].
Switch matrices have broad applications in redundant and broadcast systems.
Microwave and millimeter-wave switch matrices are essential components in
telecommunication systems since they enhance satellite capacity by providing full and
flexible interconnectivity between the received and transmitted signals. In satellite
payload systems mechanical switches are still used, they exhibit low loss, but are bulky.
Semiconductor versions of switch matrices are of course much more compact than their
mechanical counterparts. However, they exhibit high insertion loss and, moreover, they
need a constant supply of DC and are therefore power consuming. RF-MEMS switches
are referred to the solution to overcome these drawbacks. They still have mechanical
switching parts, but are compact and show a good RF performance even under near-zero
power supply. To control switching matrices, hundreds of RF-MEMS switches should be
simultaneously controlled according to the permutation. Thus a good control algorithm
for switching matrices is very important.
1.2 Project Description
In the design of large order switching matrices a modular approach using basic
switching circuits as building blocks is favorable since it implies the optimization of few
components and easily allows extending the order of the matrix. Different network
topologies can be adopted, such as the Benes network shown in Figure 1. For different
network topologies, we should study an algorithm suitable for it best.
Figure 1 16-inputs/16-outputs Benes network
In this thesis, we focus on Benes network and its control algorithm that is mapping
inputs and outputs. Benes network is made up of Double Pole Double Throw (DPDT)
that is shown in Figure 2. DPDT has two states – parallel state and cross state, which is
shown in Figure 3 [8]. Figure 4 is 4-input/4-output Benes network, which is composed
by 6 DPDTs. Hence, if we change the state of a DPDT, we can change the input-output
connection situation. Thus, the main work of our thesis is control the state of DPDTs in a
Benes network, so that the Benes network satisfies input-output requirement. The thesis is pided into three parts:
a) Doing the literature research on state-of-the-art control algorithms for Benes
networks. Find suitable algorithms have to be realized for the 16-input/16-output
RF-MEMS switch matrices using Matlab and its GUI (Graphical User Interface).
b) Find suitable algorithms have to be realized for the 12-input/12-output RF-
MEMS switch matrices using Matlab and its GUI.
c) Design the layout for the complete DC control network on a multilayer LTCC
board to reduce the number of DC switches should be controlled.
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