Date/Time: Wednesday, April 3, 2013 / 2:00 pm – 4:00 pm.

Location: Carleton University, Department of Electronics (DoE), Mackenzie Engineering Building, Room ME 4124, 1125 Colonel By Drive, Ottawa, Ontario, Canada.

Parking: Paid parking.

Registration: Free but required. To ensure a seat, please contact Qingsheng Zeng (qingsheng.zeng@crc.gc.ca)

Organizer: Dr. Qingsheng Zeng

Organizer e-mail: qingsheng.zeng@crc.gc.ca

Organized by: The IEEE Ottawa Antennas and Propagation Society and Microwave Theory & Techniques Society (AP/MTT) Joint Chapter, Electromagnetic Compatibility (EMC) Chapter, Components, Packaging and Manufacturing Technology (CPMT) Chapter, Communications Society, Broadcast Technology Society, and Consumer Electronics Society (ComSoc/BTS/CES) Joint Chapter, IEEE Ottawa Section (OS), and Department of Electronics at Carleton University (DoE Carleton).

Abstract:

Wireless communications signals have evolved greatly over the past century, from the use of Morse Code to very complicated digital modulation schemes used in wideband CDMA (WCDMA) and 3GPP Long-term evolution (LTE). This progression challenges the design of transmitters to be simultaneously energy efficient, low distortion, and spectrally clean. The increasing peak-to-average power ratio (PAPR) characteristic of these signals is a particular problem. Because it is important to understand why this is happening this presentation begins with a discussion of the physical implications of Shannon’s Capacity Limit combined with the Fourier Transform.

A ‘backwards’ design perspective is then presented, where we begin design from a maximally energy efficient circuit (a switch) and then make it generate the required signals, instead of the conventional approach of beginning with linear circuitry and then finding ways to improve its energy efficiency. This directly leads to the design and implementation of polar-modulation to improve both the energy efficiency of the power amplifier and effective linearity of the transmitter. Design of intentionally compressed circuitry is very different from conventional linear amplifier techniques, and these new design techniques will be discussed.