A tunable filter reduces the total number of filters used in TDD (Time-Division Duplex) communication circuitry. The communication circuitry may include a tunable filter and a first switch associated with the tunable filter. The tunable filter may include a tuning component and a filtering component. The tuning component may be located with the first switch on a first die. The filtering component may be located in a laminate underneath the first switch. Power amplifiers for amplifying transmission signals may be located on a second die, and the second die may be located on the laminate.

A radio frequency identification (RFID) system for frequency multiplexing includes, in an exemplary embodiment, an RFID interrogator configured for generating an RFID signal, wherein a channel frequency of the RFID signal changes over time within an operating bandwidth; and one or more electromagnetic transmissive elements each extending between a first end thereof and a second end thereof, each of the electromagnetic transmissive elements electrically coupled with the RFID interrogator at the first end thereof, each of the electromagnetic transmissive elements comprising a frequency dependent load at the second end thereof and configured for transmitting the RFID signal from the RFID interrogator to the frequency dependent load, wherein the frequency dependent load presents different electromagnetic characteristics to the RFID signal transmitted to the frequency dependent load depending on the channel frequency of the RFID signal. Other embodiments include a method for frequency multiplexing including similar components.

A system or method that receives a current request from a client, and responds to the current request based on signal strength associated with a previous request. If the current request is received on a non-preferred communication band, and a previous request was received on a preferred communication band within a pre-determined time, the system determines whether the signal strength associated with the previous request is weaker than a pre-determined threshold signal strength level for the preferred communication band. If so, the system responds to the current request. Otherwise, the system ignores the current request. If no recent request on the preferred communication band is received, and the signal strength associated with the current request is weaker than a pre-determined threshold signal strength level for the non-preferred communication band, the system responds to the current request on the non-preferred communication band. Otherwise, the system ignores the current request.

Embodiments of a tunable radio frequency (RF) diplexer and methods of duplexing transmission and receive signals are disclosed. In one embodiment, the RF diplexer includes a first hybrid coupler, a second hybrid coupler, and an RF filter circuit, and a phase inversion component. Both the RF filter circuit and the phase inversion component are connected between the first hybrid coupler and the second hybrid coupler. In some embodiments, the phase inversion component is provided by the RF filter circuit, while in other embodiments, the phase inversion component is provided separately. The phase inversion component is configured to provide a differential phase shift. The benefit of introducing the differential phase shift is that it provides increased isolation and broadband isolation between the different frequency bands being diplexed by the RF diplexer.

Embodiments of a tunable radio frequency (RF) diplexer and methods of duplexing transmission and receive signals are disclosed. In one embodiment, the RF diplexer includes a first hybrid coupler, a second hybrid coupler, and an RF filter circuit, and a phase inversion component. Both the RF filter circuit and the phase inversion component are connected between the first hybrid coupler and the second hybrid coupler. In some embodiments, the phase inversion component is provided by the RF filter circuit, while in other embodiments, the phase inversion component is provided separately. The phase inversion component is configured to provide a differential phase shift. The benefit of introducing the differential phase shift is that it provides increased isolation and broadband isolation between the different frequency bands being diplexed by the RF diplexer.

An electronic device and method for providing a communication service are provided. The method of operating an electronic device includes: receiving a first signal transmitted through a first band and a second signal transmitted through a second band; determining a communication mode of the electronic device for processing the first signal and the second signal based on device information or environment information of the electronic device; and processing the first signal and the second signal using at least one of a first modem or a second modem functionally connected to the electronic device based on the communication mode, wherein the processing of the first signal and the second signal includes: processing, when the communication mode is a first mode, the first signal in the first modem and the second signal in the second modem; and processing, when the communication mode is a second mode, the first signal and the second signal in the first modem.

An electronic device and method for providing a communication service are provided. The method of operating an electronic device includes: receiving a first signal transmitted through a first band and a second signal transmitted through a second band; determining a communication mode of the electronic device for processing the first signal and the second signal based on device information or environment information of the electronic device; and processing the first signal and the second signal using at least one of a first modem or a second modem functionally connected to the electronic device based on the communication mode, wherein the processing of the first signal and the second signal includes: processing, when the communication mode is a first mode, the first signal in the first modem and the second signal in the second modem; and processing, when the communication mode is a second mode, the first signal and the second signal in the first modem.

RF front-end circuitry, which includes RF switching and duplexing circuitry, a first RF diplexer, and a second RF diplexer, is disclosed. The RF switching and duplexing circuitry operates in one of a group of RF transmit modes, such that the group of RF transmit modes includes at least one transmit uplink carrier aggregation mode. The RF switching and duplexing circuitry provides at least one RF transmit signal based on the one of the group of RF transmit modes. The first RF diplexer is coupled between the RF switching and duplexing circuitry and a primary RF antenna. The second RF diplexer is coupled between the RF switching and duplexing circuitry and an auxiliary RF antenna.

RF front-end circuitry, which includes RF switching and duplexing circuitry, a first RF diplexer, and a second RF diplexer, is disclosed. The RF switching and duplexing circuitry operates in one of a group of RF transmit modes, such that the group of RF transmit modes includes at least one transmit uplink carrier aggregation mode. The RF switching and duplexing circuitry provides at least one RF transmit signal based on the one of the group of RF transmit modes. The first RF diplexer is coupled between the RF switching and duplexing circuitry and a primary RF antenna. The second RF diplexer is coupled between the RF switching and duplexing circuitry and an auxiliary RF antenna.

A tunable filter reduces the total number of filters used in TDD (Time-Division Duplex) communication circuitry. The communication circuitry may include a tunable filter and a first switch associated with the tunable filter. The tunable filter may include a tuning component and a filtering component. The tuning component may be located with the first switch on a first die. The filtering component may be located in a laminate underneath the first switch. Power amplifiers for amplifying transmission signals may be located on a second die, and the second die may be located on the laminate.