Agency for Science, Technology and Research

Halliburton Energy Services, Inc.

National University of Singapore

Yan Wah Michael Chia

Yijun Zhou

Jee Khoi Yin

Glenn Andrew Wilson

Zhining Chen

Xianming Qing

Yongxin Guo

Teck Hwee Lim

Piew Yoong Chee

Wing Fai Loke

Chai Moy Karen Ang

A method of spatial modulation using an antenna array including radiating elements having power amplifiers communicatively coupled thereto. An amplitude of an output signal to be formed in space is determined by the antenna array based on an input signal. Output amplitude levels for the radiating elements are determined based on the amplitude of the output signal and a current output amplitude level of the antenna array. The first signal(s) for a first subarray of the antenna array and the second signal(s) for a second subarray of the antenna array are generated based on the input signal. The output amplitude levels are assigned to the power amplifiers of the radiating elements. The first signal(s) are sent to radiating elements of the first subarray and the second signal(s) are sent to radiating elements of the second subarray for transmission therefrom to form a combined signal in space as the output signal.

Spatial modulation system and method thereof

A method for performing dual mode imaging of a borehole determines a reference point in a geological formation in response to a resistivity measurement of the formation. The reference point is associated with a feature, such as a fracture, in the formation. A tilt angle of the feature is determined, with respect to the reference point, in response to the received electromagnetic signals from the formation. For example a time-of-flight, ranging operation may be performed or an attenuation and phase change of the received signals may be determined to image the feature.

Dual mode electromagnetic imaging of a borehole

A sensing system includes a magnetic induction sensor. The magnetic induction sensor includes an induction coil for measuring a magnetic induction and for providing an output electrical signal representative of at least one component of the magnetic induction. The magnetic induction sensor further includes an electro-optical transducer for converting the electrical signal into an optical signal. The magnetic induction sensor also includes at least one impedance matching circuit electrically connected with an output of the induction coil and electrically connected with an input of the electro-optical transducer. The sensing system further includes at least one fiber optic sensing cable coupled to the magnetic induction sensor that optically communicates optical signals from the magnetic induction sensor.

Fiber optic magnetic induction (B-field) sensors

A high efficiency linear amplifier is disclosed. The amplifier comprises an input module having an input coupled to receive an input signal, a first output configured to provide a first signal component, and a second output configured to provide a second signal component. The amplifier also comprises a switching module having a switch input coupled to receive a switch signal, a first input coupled to the first output of the input module, a second input coupled to the second output of the input module, and at least a first output configured to provide a first composite signal. The amplifier further comprises an amplifier module having at least a first input coupled to the first output of the switching module and at least a first output, wherein the first and second signal components comprise constant envelope phase varying signals having different phase relationships and which correspond to the input signal, and wherein the first composite signal comprises temporally sequenced portions of the first and second signal components.

High efficiency linear amplifier

An apparatus for generating a plurality of signals is provided. The apparatus provided includes a first signal generation unit, including an input receiving a reference signal, and a plurality of outputs providing a first plurality of output signals being generated based on the reference signal, wherein any two of the output signals have a different phase. The apparatus provided further includes a second signal generation unit, including at least two inputs receiving at least two signals selected from the first plurality of output signals generated by the first signal generation unit, and a plurality of outputs providing a second plurality of output signals generated by interpolating the respective phases of the received at least two signals selected from the first plurality of output signals. The apparatus provided further includes a selection unit, including a first plurality of inputs receiving the first plurality of output signals generated by the first signal generation unit, a second plurality of inputs receiving the second plurality of output signals generated by the second signal generation unit, and a plurality of outputs providing the plurality of signals wherein each of the signals is selected from the first plurality of output signals generated by the first signal generation unit and the second plurality of output signals generated by the second signal generation unit, wherein any two signals of the plurality of signals have a different phase.

Apparatus for generating a plurality of signals

A time delay apparatus for generating a plurality of phase shifted signals is described comprising a phase tuner generating a phase control signal and a phase interpolator receiving at least one digital signal and generating the plurality of phase shifted signals by phase shifting the digital signal according to the phase control signal.

Time delay apparatus

A multiple frequency band antenna is disclosed involving a first resonant portion tuned to a low frequency band; a second resonant portion tuned to a first high frequency band at frequencies higher than the low frequency band; a third resonant portion tuned to a second high frequency band at frequencies higher than the low frequency band and substantially different from the first high frequency band; and a first conductor portion forming part of the first resonant portion and the second resonant portion, the first conductor portion having a grounding point, a feeding point for providing an input signal to at least one of the first resonant portion and the second resonant portion and for receiving an output signal from at least one of the first resonant portion and the second resonant portion, and a second conductor portion electrically connected to the feeding point wherein the third resonant portion is electrically connected to the second conductor portion.

Growing community of inventors

Singapore, Singapore

Yan Wah Michael Chia