Abstract: Expandable transceivers and receivers supporting operation on multiple frequency bands and multiple carriers are disclosed. In an exemplary design, an apparatus (e.g., a wireless device, an integrated circuit (IC) chip, or circuit module) includes a low noise amplifier (LNA) and interface circuit. The LNA resides on an IC chip and includes a first/on-chip output and a second/off-chip output. The interface circuit also resides on the IC chip, is coupled to the second output of the LNA, and provides an amplified RF signal outside of the IC chip. The apparatus may further include a buffer, load circuit, and downconverter circuit. The buffer resides on the IC chip, is coupled to the first output of the LNA, and receives a second amplified RF signal from outside of the IC chip. The load circuit is coupled to the first output of the LNA. The downconverter circuit is coupled to the load circuit.

Abstract: Omni-band amplifiers supporting multiple band groups are disclosed. In an exemplary design, an apparatus (e.g., a wireless device, an integrated circuit, etc.) includes at least one gain transistor and a plurality of cascode transistors for a plurality of band groups. Each band group covers a plurality of bands. The gain transistor(s) receive an input radio frequency (RF) signal. The cascode transistors are coupled to the gain transistor(s) and provide an output RF signal for one of the plurality of band groups. In an exemplary design, the gain transistor(s) include a plurality of gain transistors for the plurality of band groups. One gain transistor and one cascode transistor are enabled to amplify the input RF signal and provide the output RF signal for the selected band group. The gain transistors may be coupled to different taps of a single source degeneration inductor or to different source degeneration inductors.

Abstract: Multiple-input multiple-output (MIMO) low noise amplifiers (LNAs) supporting carrier aggregation are disclosed. In an exemplary design, an apparatus (e.g., a wireless device, an integrated circuit, etc.) includes a MIMO LNA having a plurality of gain circuits, a drive circuit, and a plurality of load circuits. The gain circuits receive at least one input radio frequency (RF) signal and provide at least one amplified RF signal. Each gain circuit receives and amplifies one input RF signal and provides one amplified RF signal when the gain circuit is enabled. The at least one input RF signal include transmissions sent on multiple carriers at different frequencies to the wireless device. The drive circuit receives the at least one amplified RF signal and provides at least one drive RF signal. The load circuits receive the at least one drive RF signal and provide at least one output RF signal.

Abstract: Low noise amplifiers (LNAs) supporting carrier aggregation are disclosed. In an exemplary design, an apparatus (e.g., a wireless device, an integrated circuit, etc.) includes first and second amplifier circuits and a divert cascode transistor. Each amplifier circuit may include a gain transistor and a cascode transistor. The divert cascode transistor is coupled between the output of the first amplifier circuit and the gain transistor in the second amplifier circuit. The first and second amplifier circuits receive an input radio frequency (RF) signal including transmissions sent on multiple carriers at different frequencies to a wireless device. The first and second amplifier circuits and the divert cascode transistor are controlled to amplify the input RF signal and provide (i) one amplified RF signal for one set of carriers in a first operating mode or (ii) two amplified RF signals for two sets of carriers in a second operating mode.

Abstract: Low noise amplifiers (LNAs) supporting carrier aggregation are disclosed. In an exemplary design, an apparatus (e.g., a wireless device, an integrated circuit, etc.) includes an amplifier circuit, a transformer, and a plurality of downconverters. The amplifier circuit receives and amplifies an input radio frequency (RF) signal and provides an amplified RF signal. The input RF signal includes transmissions sent on multiple carriers at different frequencies to a wireless device. The transformer includes a primary coil coupled to the amplifier circuit and a plurality of secondary coils providing a plurality of output RF signals. The plurality of downconverters downconvert the plurality of output RF signals with a plurality of local oscillator (LO) signals at different frequencies. Each downconverter includes a pair of mixers that receives one output RF signal and one LO signal and provides inphase and quadrature downconverted signals for one set of carriers being received.