Triband RF Transceiver

Wireless testbeds provide the experimental facility to test the validity of algorithms and also to test different wireless system setup/configurations. In order to support the investigation into the Heterogeneous Wireless Access Network Research Testbed (HWANRT), we are currently designing and developing a triband RF transceiver.

Goal:

Design, build, and test a portable wireless transceiver board capable of operating at the following three ISM bands,

• 900 MHz

• 2.4 GHz

• 5.7 GHz

Transceiver testbed versus off-the-shelf transceiver blocks:

The developed testbed has several advantages over off-the-shelf transceiver blocks including, but not limited to:

• Convenient to perform testing at every frequency stage

• Components/designs can be changed according to the requirements of testing scenarios

• Low MDS( minimum detectable signal) (e.g., -62 dBm compared to -52 dBm for typical off-the-shelf transceiver boards)

• Better LO stability (e.g., +/- 1 ppm, +/- 2.5 ppm compared to +/- 75 ppm for typical off-the-shelf transceiver boards)

Consideration of major components:

• External LO is not required, but can be used

• Internal LO: NovaSource G2:

  o        Dual frequency bands from 45 MHz to 2.5 GHz

  o        PC controllable and standalone operation

  o        Frequency stability of +/- 1 ppm

• 2^nd internal LO: Praxsym LO:

  o        Low phase noise with internal frequency reference

  o        Computer controlled, with stability of +/- 2.5 ppm.

• Tripler is used

• Component supplies:

  o        Minicircuits

  o        Microwave Circuits

  o        Nova Engineering

  o        Marki Microwave

  o        Pasternack Entp

  o        Praxsyms

  o        Staffol Brothers

High-level block diagram:

Design block diagram:

Transceiver board:

Top view		Bottom view

Testing:

		Input signal
		Signal modulated to 70 MHz
		Signal up-converted to 2.4 GHz
		Signal transmitted
		Signal down-converted to 70 MHz
		Signal filtered and amplified
		Output signal