Analog Devices International Unlimited Company

Si-Ware Systems

Mohamed Weheiba

Mohamed Moussa Ramadan Esmael

Mohamed Mobarak

Ayman Ahmed

Nabil Sinoussi

Ahmed A Helmy

Ahmed H A Razek

Bias arrangements for amplifiers are disclosed. An example arrangement includes a bias circuit, configured to produce a bias signal for the amplifier, and a linearization circuit, configured to improve linearity of the amplifier by modifying the bias signal based on an RF signal indicative of an RF input signal to be amplified by the amplifier. The linearization circuit includes a bias signal input for receiving the bias signal, an RF signal input for receiving the RF signal, and an output for providing a modified bias signal. The linearization circuit further includes at least a first linearization transistor, having a first terminal, a second terminal, and a third terminal, where each of the bias signal input and the RF signal input of the linearization circuit is coupled to the first terminal of the first linearization transistor, and the output of the linearization circuit is coupled to the third terminal of the first linearization transistor.

Bias arrangements with linearization transistors sensing RF signals and providing bias signals at different terminals

Bias arrangements for amplifiers are disclosed. An example bias arrangement for an amplifier includes a bias circuit, configured to produce a bias signal for the amplifier; a linearization circuit, configured to improve linearity of the amplifier by modifying the bias signal produced by the bias circuit to produce a modified bias signal to be provided to the amplifier; and a coupling circuit, configured to couple the bias circuit and the linearization circuit. Providing separate bias and linearization circuits coupled to one another by a coupling circuit allows separating a linearization operation from a biasing loop to overcome some drawbacks of prior art bias arrangements that utilize a single biasing loop.

Bias arrangements for improving linearity of amplifiers

A substantially temperature-independent LC-based oscillator uses bias control techniques. Temperature independence may be achieved by controlling the harmonic frequency content of the output of the oscillator by controlling the amplitude. Amplitude control may be achieved by inserting a control mechanism in the feedback loop of the oscillator.

Method and apparatus to control the LC tank temperature null characteristic in a highly stable LC oscillator

Growing community of inventors

Cairo, Egypt

Mohamed Weheiba