Variable attenuator
AssigneeSumitomo Electric Device Innovations, Inc.
InventorsAkio Oya, Makoto Kondo
Life of this patent
Estimating the term…
Abstract
A variable attenuator (v-ATT) is disclosed. The v-ATT includes an input terminal, an output terminal, a transmission line between the input and output terminals, at least two stages provided between the transmission line and the ground, and a bias unit. Each of the stages includes a field effect transistor (FET) that varies impedance between the transmission line and the ground according to a bias provided to the gate thereof. The bias unit generates the biases each provided to the stages. One of the features of the v-ATT is that at least one of the stages receives at least one of the biases that is different from biases provided to other of the at least one of the stages.
Claims8
A variable attenuator, comprising:
- an input terminal that receives a signal containing high frequency components;
- an output terminal that outputs another signal attenuated from the signal received at the input terminal;
- a transmission line that couples the input terminal with the output terminal, the transmission line;
- a first stage connected between the transmission line and a ground, the first stage including a first field effect transistor (FET) having a gate, a current terminal connected with the transmission line, and another current terminal connected to the ground, the FET varying impedance between the current terminal and the another current terminal according to a first bias supplied to the gate;
- a second stage connected between the transmission line and the ground, the second stage including a second FET having gate, a current terminal connected with the transmission line, and another current terminal connected to the ground, the second FET varying impedance between the current terminal and the another current terminal thereof according to a second bias supplied to the gate thereof;
- a bias unit including an input, the bias unit generating the first bias and the second bias according to a control signal provided to the input of the bias unit, the bias unit supplying the first bias to the first stage and the second bias to the second stage,
- wherein the first bias is different from and independent of the second bias.
Dependencies are inferred from the claim text.