الفهرس Only 14 pages are availabe for public view
 |  | from | 134 |  |  |
| | | from | 134 | | |
Abstract
In this thesis we present a frequency synthesizer for the Multi band OFDM (MB-OFDM) standard which is a standard for presonal wireless application such as wireless USB and BlueTooth 3.0. The standard divides the spectrum between 3.1 to 10.6 GHz into 14 bands each is 528 MHz wide, where the data is transmitted across the bands using a frequency hopping spread spectrum modulation technique.
The tough hopping time imposed by the standard (9.5 ns) and the wide frequency
range required to cover (7 GHz), are the main challenges facing the design of the frequency synthesizer circuits of this standard.
The design presented here covers the whole 14 bands of the standard(3.1-10.6 GHz), with a hopping time below 2 ns. A dual PLL architecture was used where one PLL provides the required frequency while the other is still locking, a high speed multiplexer is then used
to switch between the outputs of the two PLLs based on the signals coming from the digital control circuit. The 528 MHz reference frequency required by both PLLs is provided by a third reference PLL. The two main PLLs are integer-N PLLs with a lock time of 150 ns and a bandwidth of 33 MHz.
The circuits are desinged using SMIC 90nm technology node. It takes a die area of 0.08 mm2, and a power consumption of 76.5 mW from two power supplies 1/2.5 V