Abstract:
A radio frequency (RF) switch adapted to reduce third order intermodulation (IM3) products generated as RF signals propagate through the RF switch is disclosed. The RF switch includes N semiconductor switch segments, and N−1 phase shift networks, individual ones of the N−1 phase shift networks being coupled between adjacent ones of the N semiconductor switch segments where N is a natural number greater than 1. In operation, when the RF switch is on, IM3 products generated by the RF switch propagating through the N−1 phase shift networks are phase shifted such that the IM3 products are at least partially canceled.
Abstract:
Embodiments disclosed herein relate to programmable duplexers. The frequency pass band of the programmable duplexer is changed according to a selection of a channel-pair selection to control or maximize the transition band between the receiver path and the transmitter path. The programmable duplexer permits selections of desired pass bands without the need for multiple duplexer filters. As an additional advantage, the transmission band requirements become less sensitive to manufacturing tolerances and temperature variations.
Abstract:
An RF system for suppressing third-order intermodulation (IM3) products is disclosed. The RF system is made up of a plurality of branches coupled in parallel. Each of the plurality of branches includes a positive phase shift network, a negative phase shift network, and nonlinear components, wherein the nonlinear components are coupled between the positive phase shift network and the negative phase shift network. The RF system also includes a null offset branch with nonlinear components that are coupled in parallel with the plurality of branches. In one embodiment, the nonlinear components are series stacked field effect transistors (FETs) that comprise an RF switch having a switch segment for the null offset branch and a switch segment for each of the plurality of branches. The RF switch further includes a control terminal for turning the FETs on and off.
Abstract:
Embodiments disclosed herein relate to programmable duplexers. The frequency pass band of the programmable duplexer is changed according to a selection of a channel-pair to control or maximize the transition band between the receiver path and the transmitter path. The programmable duplexer permits selections of desired pass bands without the need for multiple duplexer filters.Embodiments disclosed herein also relate to temperature compensating a programmable duplexer based upon one or more temperature indications. The one or more temperature indications may be based upon a temperature of a semiconductor circuit, a temperature of a substrate of a one-port resonator of the programmable duplexer, and/or a temperature of the one-port resonator. The resulting programmable duplexer has an added additional advantage of lessening the temperature variations of the programmable duplexer.
Abstract:
An RF system for reducing intermodulation (IM) products is disclosed. The RF system includes a first nonlinear element and a second nonlinear element, wherein the second nonlinear element generates inherent IM products and the first nonlinear element is adapted to generate compensating IM products. Alternatively, the first nonlinear element generates inherent IM products and the second nonlinear element is adapted to generate compensating IM products. The amplitudes of the compensating IM products are substantially equal to amplitudes of the inherent IM products. The RF system further includes a phase shifter that is adapted to provide a phase shift that results in around 180° of phase shift between the inherent IM products and the compensating IM products. The phase shifter is coupled between the first nonlinear element and the second nonlinear element.
Abstract:
A radio frequency (RF) switch adapted to reduce third order intermodulation (IM3) products generated as RF signals propagate through the RF switch is disclosed. The RF switch includes N semiconductor switch segments, and N−1 phase shift networks, individual ones of the N−1 phase shift networks being coupled between adjacent ones of the N semiconductor switch segments where N is a natural number greater than 1. In operation, when the RF switch is on, IM3 products generated by the RF switch propagating through the N−1 phase shift networks are phase shifted such that the IM3 products are at least partially canceled.
Abstract:
Disclosed is a diplexed transmit (TX) filter and RF switch for suppressing third order intermodulation (IM3) products. Included are first and second duplexers each having a receive (RX) port, a TX port, and an RX/TX port. Also included are first and second power splitter/combiners each having first, second, and third terminals. Further included are first, second, and third phase shift networks. The first power splitter/combiner's first terminal is coupled to the first duplexer's TX port and a first switch segment is coupled between the first duplexer's RX/TX port and the first terminal of the second coupler. The first phase shift network is coupled to the second duplexer's TX port and a second switch segment in series with the second phase shift network is coupled between the second duplexer's RX/TX port and second coupler's second terminal. The third phase shift network is coupled to the second duplexer's RX terminal.
Abstract:
An RF system for suppressing third-order intermodulation (IM3) products is disclosed. The RF system is made up of a plurality of branches coupled in parallel. Each of the plurality of branches includes a positive phase shift network, a negative phase shift network, and nonlinear components, wherein the nonlinear components are coupled between the positive phase shift network and the negative phase shift network. The RF system also includes a null offset branch with nonlinear components that are coupled in parallel with the plurality of branches. In one embodiment, the nonlinear components are series stacked field effect transistors (FETs) that comprise an RF switch having a switch segment for the null offset branch and a switch segment for each of the plurality of branches. The RF switch further includes a control terminal for turning the FETs on and off.
Abstract:
A longitudinally coupled leaky surface acoustic wave (LSAW) resonator filter has a wide bandwidth, low insertion loss and return loss characteristics, and high power handling capability. The LSAW resonator filter includes a plurality of longitudinally coupled LSAW resonator tracks disposed upon a piezoelectric substrate and connected in series. The resonator tracks each include reflective gratings and interdigital transducers (IDTs) disposed end-to-end. Acoustic resonant cavities are formed between each IDT and its neighboring IDTs or gratings by chirping the fingers of the IDT in the vicinity of the cavities. Phase discontinuity is eliminated; reflective bulk acoustic wave scattering is reduced; and improved insertion loss and power handling capability are achieved.
Abstract:
An apparatus for reading radially patterned magnetic data from circular objects, such as tokens used by the gaming, transportation, entertainment and other industries. A method of reading the data from such a token.