The problems of high cost, high loss and incomplete distortion compensation are resolved in a distortion generating circuit which employs a nonlinear phase modulator (70, FIG. 7) and a linear phase shifter (71) as a means of generating selected distortion signal components. The circuit includes an output coupler (30) and an output coupler (31) interconnected by means of a pair of wavepaths (32, 33). The nonlinear phase modulator (70), which includes a nonlinear reactive element (37), is disposed...

An objective lens particularly for use in a low light level or night vision system designed to introduce a controlled amount of barrel distortion at the edges of its field of view to permit use with a flat input faced imaging tube.

A distortion preventer bead on a container body is spaced from another bead, which cooperates with an adjacent peripheral leg of a closure to provide a locking engagement of the closure and the container body, and serves to limit any pivotal motion by the leg in the direction of the container body.

In order to carry out high-precision control of distortion compensation, a received signal is split into two signals. One of the resulting signals ("the first signal") is provided to a distortion generator with similar characteristics to the distortion produced at the signal transmitting side, and the phase and amplitude of the other of the resulting signals ("the second signal") are controlled. By adding these two signals, the desired signal is suppressed and only the distortion component is ex...

The invention relates to detecting distortion in large engineering structures using one or more fibre optic cables bonded to or in the structure. An optical signal is transmitted along the cable and information is obtained from the received signal regarding the length and/or change in length of the cable.

The input signal (110) to a non-linear amplifier (112) is predistorted by injecting a correction signal at coupler (124). To generate the correction signal, a sample of the input signal is amplified using amplifier (130) which has substantially the same distortion generating characteristics as amplifier (112). The output of amplifier (130) is sampled, and the main tone energy is removed at (138), leaving the correction signal for injection to the main signal path. The main portion of the output ...

The distortion compensator which compensates the nonlinearity of a power amplifier in a radio communication device stops the operation of updating the automatic phase adjustment, automatic delay adjustment, equalizer adjustment, and distortion compensation table when something wrong is detected in the input to a distortion compensation unit such as a reference signal, feedback signal, address of the distortion compensation table, and phase value so that the distortion compensation coefficients m...

A distortion compensator for compensating for distortion produced in an amplifier that amplifies a signal includes a signal level detector for detecting a level of a signal to be amplified and a distortion compensator for conducting distortion compensation based on the detection result separately for each frequency band signal of multiple frequency band signals contained in the signal to be amplified. The distortion compensator improves distortion compensation performance by reducing the effect ...

A distortion analyzer for generating a distortion signal based on an input signal. For example, the distortion signal may be generated by adding a first signal corresponding to the entire spectrum of the input signal to a second signal corresponding to a low-frequency component of the input signal and then subtracting from the result of addition a third signal corresponding to a specific frequency band of the input signal. The effect of polarization mode dispersion that an optical signal experie...

A distortion compensator updating and selecting a distortion compensation coefficient applied to a digital transmission signal so as to reduce the difference between the digital transmission signal and a digital feedback signal is disclosed. The distortion compensator includes a control part that controls the level of an input signal to an analog-to-digital conversion part outputting the digital feedback signal in accordance with the magnitude of the amplitude of the digital transmission signal.