A multi-frequency tuning circuit includes a first branch including a first inductor and a first capacitor arranged in series and a second branch including a second inductor and a second capacitor arranged in series. The circuit is arranged within a circuitry module configured to be positioned between a source and a load, the first branch and the second branch both associated with loads, from the source, having low impedance frequencies. In order to improve transmitter antenna output power for downhole tools, the tuning circuit creates high impedance at operating frequencies between frequencies corresponding to low impedance.

A multi-frequency tuning circuit includes a first branch including a first inductor and a first capacitor arranged in series and a second branch including a second inductor and a second capacitor arranged in series. The circuit is arranged within a circuitry module configured to be positioned between a source and a load, the first branch and the second branch both associated with loads, from the source, having low impedance frequencies. In order to improve transmitter antenna output power for downhole tools, the tuning circuit creates high impedance at operating frequencies between frequencies corresponding to low impedance.

A digital high-speed hybrid load pull test system comprises a slide screw automatic passive tuner, a digital active forward injection loop in a closed loop transmission configuration, calibration and tuning algorithms. The forward active injection loop comprises at least one adjustable coupler, a digital electronic tuner and feedback power amplifier; the passive tuner comprises one or more metallic tuning probes, used to create passive reflection factors. Small signal calibration of the passive and active tuners create a global calibration data base, used to pre-tune in the area of the target impedance and final high power (nonlinear) tuning employs a in-situ signal power wave search and measurement for digital impedances around the small signal pattern. The system provides for high speed low injected power tuning with maximum reflection factor at DUT reference plane reaching unity.

A digital high-speed hybrid load pull test system comprises a slide screw automatic passive tuner, a digital active forward injection loop in a closed loop transmission configuration, calibration and tuning algorithms. The forward active injection loop comprises at least one adjustable coupler, a digital electronic tuner and feedback power amplifier; the passive tuner comprises one or more metallic tuning probes, used to create passive reflection factors. Small signal calibration of the passive and active tuners create a global calibration data base, used to pre-tune in the area of the target impedance and final high power (nonlinear) tuning employs a in-situ signal power wave search and measurement for digital impedances around the small signal pattern. The system provides for high speed low injected power tuning with maximum reflection factor at DUT reference plane reaching unity.

A tunable inductor arrangement includes a first winding part connected at one end to a first input of the inductor arrangement, a second winding part connected at one end to the other end of the first winding part, a third winding part connected at one end to a second input of the inductor arrangement, and a fourth winding part connected at one end to the other end of the third winding part. For tuning, the inductor arrangement includes a switch arrangement switchable between a first setting series-connecting the first and third winding parts between the inputs, and a second setting series-connecting the first, second, fourth and third winding parts between the inputs. The first and third winding parts are arranged on a chip or substrate with essentially common magnetic fields, and the second and fourth winding parts are arranged to cancel electro-magnetic coupling with the first and third winding parts.

A digital high-speed hybrid load pull test system comprises a slide screw automatic passive tuner, a digital active forward injection loop in a closed loop transmission configuration, calibration and tuning algorithms. The forward active injection loop comprises at least one adjustable coupler, a digital electronic tuner and feedback power amplifier; the passive tuner comprises one or more metallic tuning probes, used to create passive reflection factors. Small signal calibration of the passive and active tuners create a global calibration data base, used to pre-tune in the area of the target impedance and final high power (nonlinear) tuning employs a in-situ signal power wave search and measurement for digital impedances around the small signal pattern. The system provides for high speed low injected power tuning with maximum reflection factor at DUT reference plane reaching unity.

A digital high-speed hybrid load pull test system comprises a slide screw automatic passive tuner, a digital active forward injection loop in a closed loop transmission configuration, calibration and tuning algorithms. The forward active injection loop comprises at least one adjustable coupler, a digital electronic tuner and feedback power amplifier; the passive tuner comprises one or more metallic tuning probes, used to create passive reflection factors. Small signal calibration of the passive and active tuners create a global calibration data base, used to pre-tune in the area of the target impedance and final high power (nonlinear) tuning employs a in-situ signal power wave search and measurement for digital impedances around the small signal pattern. The system provides for high speed low injected power tuning with maximum reflection factor at DUT reference plane reaching unity.

An optoelectronic oscillator (OEO) is disclosed comprising an electronically tunable filter for transposing narrow pass band characteristics of a surface acoustic wave (SAW) filter to a microwave frequency to provide mode selection in the OEO. An OEO is disclosed comprising a set of optical domain components, a downconverter in communication with an output of the optical domain components, and a set of radio frequency (RF) domain components in communication with an output of the downconverter. The set of RF domain components comprises a tunable filter operating at a filter center frequency and having an output coupled to the set of optical domain components for communicating a mode selection result. The tunable filter including a tuner; and a sub-filter. The sub-filter operating at a fixed center frequency to provide mode selection and adjacent mode suppression with respect to the tunable filter center frequency. The sub-filter center frequency being lower than the tunable filter center frequency, and a ratio of the tunable filter center frequency to a bandwidth of the sub-filter being at least 1000:1.

An optoelectronic oscillator (OEO) is disclosed comprising an electronically tunable filter for transposing narrow pass band characteristics of a surface acoustic wave (SAW) filter to a microwave frequency to provide mode selection in the OEO. An OEO is disclosed comprising a set of optical domain components, a downconverter in communication with an output of the optical domain components, and a set of radio frequency (RF) domain components in communication with an output of the downconverter. The set of RF domain components comprises a tunable filter operating at a filter center frequency and having an output coupled to the set of optical domain components for communicating a mode selection result. The tunable filter including a tuner; and a sub-filter. The sub-filter operating at a fixed center frequency to provide mode selection and adjacent mode suppression with respect to the tunable filter center frequency. The sub-filter center frequency being lower than the tunable filter center frequency, and a ratio of the tunable filter center frequency to a bandwidth of the sub-filter being at least 1000:1.

An optoelectronic oscillator (OEO) is disclosed comprising an electronically tunable filter for transposing narrow pass band characteristics of a surface acoustic wave (SAW) filter to a microwave frequency to provide mode selection in the OEO. An OEO is disclosed comprising a set of optical domain components, a downconverter in communication with an output of the optical domain components, and a set of radio frequency (RF) domain components in communication with an output of the downconverter. The set of RF domain components comprises a tunable filter operating at a filter center frequency and having an output coupled to the set of optical domain components for communicating a mode selection result. The tunable filter including a tuner; and a sub-filter. The sub-filter operating at a fixed center frequency to provide mode selection and adjacent mode suppression with respect to the tunable filter center frequency. The sub-filter center frequency being lower than the tunable filter center frequency, and a ratio of the tunable filter center frequency to a bandwidth of the sub-filter being at least 1000:1.