Frequency translation and applications of same are described herein, including wireless local area network (WLAN) applications such as IEEE Standard 802.11 WLANs. Such applications include, but are not limited to, frequency down-conversion, frequency up-conversion, enhanced signal reception, unified down-conversion and filtering, and combinations and applications of same.

Wireless local area network (WLAN) technology and applications including techniques of universal frequency translation

Methods, systems, and apparatuses, and combinations and sub-combinations thereof, for down-converting and up-converting an electromagnetic (EM) signal are described herein. Briefly stated, in embodiments the invention operates by receiving an EM signal and recursively operating on approximate half cycles (½, 1½, 2½, etc.) of the carrier signal. The recursive operations can be performed at a sub-harmonic rate of the carrier signal. The invention accumulates the results of the recursive operations and uses the accumulated results to form a down-converted signal. In an embodiment, the EM signal is down-converted to an intermediate frequency (IF) signal. In another embodiment, the EM signal is down-converted to a baseband information signal. In another embodiment, the EM signal is a frequency modulated (FM) signal, which is down-converted to a non-FM signal, such as a phase modulated (PM) signal or an amplitude modulated (AM) signal. Up-conversion is accomplished by controlling a switch with an oscillating signal, the frequency of the oscillating signal being selected as a sub-harmonic of the desired output frequency.

Method and system for down-converting and up-converting an electromagnetic signal, and transforms for same

The present invention includes a system and method for ensuring reception of a communications signal. A modulating baseband signal with desired information is accepted, and a plurality of redundant spectrums is generated. Each redundant spectrum comprises the necessary amplitude, phase, and frequency information to substantially reconstruct the modulating baseband signal. It is expected but not required that the redundant spectrums will be generated at a first location and sent to a second location over a communications medium. At the second location, the redundant spectrums are independently processed to recover a demodulating baseband signal for each of the redundant spectrums. In one embodiment, an error detection process is employed at the second location to detect and eliminate those demodulated baseband signals that have been corrupted during transmission. An error-free demodulated baseband signal is selected from the remaining demodulated baseband signals. The error-free demodulated baseband signal is representative of the modulating baseband signal sent over the communications medium.

Method and system for ensuring reception of a communications signal

Methods and apparatuses for reducing DC offsets in a communication system are described. In a first aspect, a feedback loop circuit reduces DC offset in a wireless local area network (WLAN) receiver channel. The frequency response of the feedback loop circuit can be variable. In a second aspect, a circuit provides gain control in a WLAN receiver channel. First and second automatic gain control (AGC) amplifiers are coupled in respective portions of the receiver channel. Circuits for monitoring DC offset, and for providing control signals for controlling the frequency response of the DC offset reducing circuits are also provided.

Method and apparatus for reducing DC offsets in a communication system

A communication system comprising a multi-protocol, multi-bearer sub-system is described herein. The sub-system is a universal platform module that can transmit and receive one or more information signals in one or more protocols using one or more bearer services. In one embodiment, the sub-system may form a portion of a transceiver that is composed of a transmitter and a receiver, and which is a gateway server between a personal area network (PAN) and the global wireless network.

Universal platform module and methods and apparatuses relating thereto enabled by universal frequency translation technology

A singly-balanced active mixer circuit is disclosed for developing an IF signal by combining an RF signal and a local oscillator (LO) signal. The RF and LO signals are applied to a strip transmission line ring which provides balanced components of the LO signal to a pair of active devices arranged in an singly-balanced active mixer. The active devices are coupled directly, or via a balanced PI-network to the primary winding of an output transformer for application to the following IF stage of the radio receiver. DC biasing of the active devices is provided via a floating tap on the primary winding of the output transformer which is not bypassed at the input, LO and IF frequencies. The singly balanced active mixer circuit may be advantageously utilized in a radio having a receiver with broadband front-end RF selectivity.

Singly-balanced active mixer circuit

A singly-balanced active mixer circuit is disclosed for developing an IF signal by combining an RF signal and a local oscillator (LO) signal. The RF and LO signals are applied to a strip transmission line ring which provides balanced components of the LO signal to a pair of active devices arranged in a singly-balanced active mixer. The active devices are coupled directly, or via a balanced PI-network to the primary winding of an output transformer for application to the following IF stage of the radio receiver. The singly balanced active mixer circuit may be advantageously utilized in a radio having a receiver with broadband front-end RF selectivity.

George D. Helm

Papers

Singly-balanced active mixer circuit

Balanced active mixer circuit