Abstract: A digital receiver (200) and transmitter (300), wherein the digital receiver includes a plurality of antennas (202) for receiving uplink radio frequency signals; a plurality of analog to digital converters (210) for converting the received radio frequency signals into digital signals; a switched digital down converter (214) for down converting one of the digital signals to a baseband IF signal; and a channel processor (228) for recovering one of a plurality of communication channels contained within the baseband IF signal.

Abstract: A multi-channel digital transceiver (400) receives uplink radio frequency signals and converts these signals to digital intermediate frequency signals. Digital signal processing, including a digital converter module (426), is employed to select digital intermediate frequency signals received at a plurality of antennas (412) and to convert these signals to baseband signals. The baseband signals are processed to recover a communication channel therefrom. Downlink baseband signals are also processed and digital signal processing within the digital converter module (426) up converters and modulates the downlink baseband signals to digital intermediate frequency signals. The digital intermediate frequency signals are converted to analog radio frequency signals, amplified and radiated from transmit antennas (420).

Abstract: A multi-channel digital transceiver (400) receives uplink radio frequency signals and converts these signals to digital intermediate frequency signals. Digital signal processing, including a digital converter module (426), is employed to select digital intermediate frequency signals received at a plurality of antennas (412) and to convert these signals to baseband signals. The baseband signals are processed to recover a communication channel therefrom. Downlink baseband signals are also processed and digital signal processing within the digital converter module (426) up converters and modulates the downlink baseband signals to digital intermediate frequency signals. The digital intermediate frequency signals are converted to analog radio frequency signals, amplified and radiated from transmit antennas (420).

Abstract: A multi-channel digital transceiver (400) receives uplink radio frequency signals and converts these signals to digital intermediate frequency signals. Digital signal processing, including a digital converter module (426), is employed to select digital intermediate frequency signals received at a plurality of antennas (412) and to convert these signals to baseband signals. The baseband signals are processed to recover a communication channel therefrom. Downlink baseband signals are also processed and digital signal processing within the digital converter module (426) up converters and modulates the downlink baseband signals to digital intermediate frequency signals. The digital intermediate frequency signals are converted to analog radio frequency signals, amplified and radiated from transmit antennas (420).

Abstract: A method of controlling an apparatus with a control signal responsive to a feedback signal comprises: detecting when a feedback signal is not being received; determining whether a control signal is being provided; and adjusting the control to the apparatus depending on whether the control signal is being provided. An apparatus for performing this method comprises a programmed computer and a control signal feedback circuit for providing to the programmed computer a signal indicating whether a valid control signal is being provided.

Abstract: The present invention is an improved apparatus and method for measuring downhole flowing and shut-in pressures to determine the condition of the reservoir and the potential of the well as a stimulation candidate. The tool string of the present invention is a novel combination of existing equipment that allows an electronic pressure gauge and shut-in tool to be run into the hole with coiled tubing. The present invention, in most cases, solves the potential problem of having to shut in or kill a flowing well prior to and after performing pressure testing, preventing lost production or potential well damage due to the killing operation. In addition, the present invention provides accuracy over current coiled tubing systems by reducing the effects of wellbore storage on pressure build-up testing.

Abstract: A system is provided for mixing of concentrated liquid gelling agent and water to form a fracturing fluid for fracturing of a subterranean formation. High shear rotary mixers are utilized in a blender tub to provide efficient hydration of the concentrated liquid gelling agent and water mixture.

Abstract: A channelized receiver system for use in conjunction with a scanning antenna wherein a received rf signal is provided to a plurality of filters each of which has a passband corresponding to a portion of a search bandwidth. The filter output signals are processed to provide a signal related to the frequency of the received rf signal for tuning a narrow band, superheterodyne/receiver to the frequency of the received rf signal. More particularly, the received rf signal is divided so that a first portion is applied to a first group of filters, and a second portion applied to a second group of filters. The filters in each group have passbands defining non-contiguous portions of the search bandwidth. The invention also provides a voting logic circuit in which outputs from each of the filters in each filter group are processed to determine which filter in each group has the highest output signal. Circuitry is provided for comparing these output signals to predetermined amplitude and width criteria.