| 摘要 |
<p>An integrated circuit (IC) includes a variable gain high frequency low noise amplifier (LNA) that receives a high frequency input signal and comprises a variable gain amplifier and a filter. The variable gain amplifier receives gain control signals that set the amount of gain applied to the input signal to create an amplifier output signal. The filter comprises passive components including inductors, capacitors and resistors. The filter also includes parasitic inductances provided by package leads and bond leads/wires. The variable gain amplifier includes a current steering mechanism that is responsive to the gain control signals, and sets the desired amplifier gain in response to the control signals by steering the input signal between a load and the filter. The filter is constructed from package leads, bond wires and dedicated on-chip components that overcome the lack of a precise on-chip RF ground to provide the requisite isolation between the input signal and the amplifier output signal. Significantly, the filter overcomes the lack of a good ground on the IC.</p> |
