Abstract: An antibody may be capable of specifically binding CD137 or an antigen binding fragment thereof, wherein the light chain variable region and the heavy chain variable region have one or more mutations. The antibody or antigen binding fragment thereof may be used in preparing a drug. The antibody or an antigen binding fragment thereof may specifically bind CD137, and may include a light chain variable region VL and a heavy chain variable region VH, wherein compared to a sequence as shown in SEQ ID NO: 103, the VL comprises one or more VL amino acid mutations, and the VL amino acid mutation occurs at one or more positions: V3, A10, K44, D71, and/or V77.

Abstract: A signal processing system includes a modulation system and a transmission system. The modulation system is configured to perform first modulation processing on a first subcarrier signal to obtain a second subcarrier signal. The modulation system is further configured to perform second modulation processing on the second subcarrier signal and a first signal light to obtain a transmission signal light. The transmission signal light includes a single-frequency optical carrier signal and an optical sideband signal, and a frequency band of the single-frequency optical carrier signal and a frequency band of the optical sideband signal do not completely overlap. The transmission system is configured to transmit the transmission signal light.

Abstract: An apparatus includes a signal modulator configured to receive a radio frequency (RF) input signal having frequency bands and spanning a first frequency range within a second frequency range, and provide down-converted signals by converting each frequency band of the RF input signal down to a target frequency range. The apparatus further includes digital RF memories (DRFMs) configured to provide intermediate interfering signals by modulating at least one of the down-converted signals, and an interfering signal generator configured to provide up-converted signals by converting the intermediate interfering signals collectively up to a third frequency range, wherein the third frequency range is within the second frequency range, and provide an interfering RF output signal by combining the up-converted signals, wherein the interfering RF output signal spans the third frequency range.

Abstract: An apparatus comprises an optical signal generator configured to provide a first radiation comprising a first nominal carrier frequency and a second nominal carrier frequency, and provide a second radiation comprising a third nominal carrier frequency and a fourth nominal carrier frequency; an optical to electrical converter coupled to the optical signal generator and configured to: generate a first electrical current based on the first radiation and the second radiation without the second radiation passing through the Device under Test (DUT); and generate a second electrical current based on the first radiation and the second radiation after the second radiation passes through the DUT; and a data processor configured to determine a transfer function of the DUT at the third nominal carrier frequency and the fourth nominal carrier frequency based on the first electrical current and the second electrical current.

Abstract: An apparatus comprises an optical signal generator configured to provide a first radiation comprising a first nominal carrier frequency and a second nominal carrier frequency, and provide a second radiation comprising a third nominal carrier frequency and a fourth nominal carrier frequency; an optical to electrical converter coupled to the optical signal generator and configured to: generate a first electrical current based on the first radiation and the second radiation without the second radiation passing through the Device under Test (DUT); and generate a second electrical current based on the first radiation and the second radiation after the second radiation passes through the DUT; and a data processor configured to determine a transfer function of the DUT at the third nominal carrier frequency and the fourth nominal carrier frequency based on the first electrical current and the second electrical current.

Abstract: An apparatus comprises an optical detecting signal generator configured to provide an optical spectrum comprising two frequency carriers, the two frequency carriers having two different nominal carrier frequencies, and the output port of the optical detecting signal generator being further configured to be coupled to a device under test (DUT); an optical to electrical converter configured to generate a first electrical current based on the optical spectrum without the optical spectrum passing through the DUT; and generate a second electrical current based on the optical spectrum after the optical spectrum passes through the DUT; and a data processor coupled to the optical to electrical converter, the data processor being configured to determine a transfer function of the DUT at an average of the two different nominal carrier frequencies based on the first electrical current and the second electrical current.

Abstract: An apparatus comprises an optical detecting signal generator configured to provide an optical spectrum comprising two frequency carriers, the two frequency carriers having two different nominal carrier frequencies, and the output port of the optical detecting signal generator being further configured to be coupled to a device under test (DUT); an optical to electrical converter configured to generate a first electrical current based on the optical spectrum without the optical spectrum passing through the DUT; and generate a second electrical current based on the optical spectrum after the optical spectrum passes through the DUT; and a data processor coupled to the optical to electrical converter, the data processor being configured to determine a transfer function of the DUT at an average of the two different nominal carrier frequencies based on the first electrical current and the second electrical current.

Abstract: An apparatus comprises a phase modulator having a first input port to receive a radiation and having a first output port to provide a first signal toward a device under test (DUT), wherein the phase modulator is configured to generate the first signal by performing phase modulation on the radiation received at the first input port; an intensity modulator having a second input port to receive the radiation and having a second output port to provide a second signal toward the DUT, wherein the intensity modulator is configured to generate the second signal by performing intensity modulation on the radiation received at the second input port; and a transfer function analyzer configured to determine a transfer function of the DUT based on the first signal and the second signal.

Abstract: An apparatus comprises a phase modulator having a first input port to receive a radiation and having a first output port to provide a first signal toward a device under test (DUT), wherein the phase modulator is configured to generate the first signal by performing phase modulation on the radiation received at the first input port; an intensity modulator having a second input port to receive the radiation and having a second output port to provide a second signal toward the DUT, wherein the intensity modulator is configured to generate the second signal by performing intensity modulation on the radiation received at the second input port; and a transfer function analyzer configured to determine a transfer function of the DUT based on the first signal and the second signal.