The Experts below are selected from a list of 6477 Experts worldwide ranked by ideXlab platform

Paul K L Yu - One of the best experts on this subject based on the ideXlab platform.

  • enhancement in third order output Intercept Point of high power photodiodes by nonlinear voltage and current dependent responsivities
    Electronics Letters, 2015
    Co-Authors: Dongsoo Shin, W S C Chang, Paul K L Yu
    Abstract:

    High-power and high-linearity photodiodes (PDs) are of critical importance to achieve high-efficiency analogue fibre links. A small-signal analysis is utilised on the nonlinear responsivity of the modified uni-travelling-carrier PDs to understand the theoretical limitation on the third-order output Intercept Point (OIP3) of the link. It is theoretically shown that a nonlinear responsivity depending on both the voltage and the current can give rise to an enhanced OIP3 at certain bias and current values.

  • behaviors of the third order Intercept Point for p i n waveguide photodiodes
    Optics Express, 2009
    Co-Authors: M N Draa, D C Scott, W S C Chang, Jeffrey Bloch, Nong Chen, Steven Bo Chen, Paul K L Yu
    Abstract:

    Waveguide PIN photodiodes with different absorber thicknesses and lengths were fabricated and characterized for linearity. Device A has a thicker absorber and shorter length, resulting in a bandwidth of 20GHz while device B reduces the absorber by half while maintaining the intrinsic layer thickness and almost doubles the length, resulting in a smaller optical overlap factor and a bandwidth of 10GHz. Device B shows a significant enhancement in OIP3 with a record high maximum value for a PIN waveguide photodiode of 42.4dBm at 28mA and -4V bias compared to device A which has a maximum OIP3 of 32.7dBm at 10mA and -4V bias. The increased linearity in device B is attributed to the reduction in optical overlap factor and increase in device length resulting in an easing of the front facet photocurrent density and overall device heating. The DC saturation Points are about 75mA and >160mA for device A and B at -2V bias.

  • frequency behaviors of third order Intercept Point for a waveguide photodiode using three laser two tone setup
    Lasers and Electro-Optics Society Meeting, 2008
    Co-Authors: M N Draa, D C Scott, W S C Chang, Paul K L Yu
    Abstract:

    A three laser two tone setup removes unwanted nonlinearities from the third order Intercept Point (IP3) measurement. A high frequency photodetector with an IP3 upwards of 30 dBm will be analyzed up to 18 GHz using the new setup and with the circuit model used in Jiang (2000).

  • the frequency behavior of the third order Intercept Point in a waveguide photodiode
    IEEE Photonics Technology Letters, 2000
    Co-Authors: Hao Jiang, D C Scott, Dongsoo Shin, G L Li, T A Vang, Paul K L Yu
    Abstract:

    In Hayes's (1993) and Williams's (1996) analyses, the photodiode nonlinearity is attributed to the space charge screening effect. In this paper, the third-order intermodulation distortions of a high frequency, large optical cavity p-i-n waveguide photodiode are characterized up to 18 GHz using a two-tone measurement. At high bias voltage, the third-order Intercept Point (IP3) of the waveguide photodiode is constant at low frequency and /spl sim/f/sup -3/ at high frequency. This closely agrees with our model, which is based upon variation of the photodiode impedance. The measured IP3 of the same device at low bias voltages indicates the contribution of space charge screening under low bias voltage or severe saturation.

Fu Li - One of the best experts on this subject based on the ideXlab platform.

  • saleh model and digital predistortion for power amplifiers in wireless communications using the third order Intercept Point
    Journal of Electronic Testing, 2019
    Co-Authors: Haider Alkanan, Xianzhen Yang, Fu Li
    Abstract:

    This paper presents a novel approach for estimating the Saleh model’s parameters using the gain and third-order Intercept Point (IP3) of a power amplifier. The IP3 is a widely used technical parameter for describing the nonlinearity of the power amplifier in wireless communications. The proposed approach minimizes an objective function of error between the third-order Taylor series and the Saleh Amplitude-to-Amplitude (AM/AM) model. This approach of the parameters estimation is also used for identifying the Digital Predistortion (DPD) to compensate for the memoryless AM/AM nonlinear distortion of power amplifiers in wireless communications. Finally, the Saleh model accuracy and DPD linearization are validated based on the WCDMA measurement signal.

  • Spectrum analysis of nonlinear distortion of RF power amplifiers for wireless signals
    International Conference on Communication Technology Proceedings 2003. ICCT 2003., 2003
    Co-Authors: Heng Xiao, Qiang Wu, Fu Li
    Abstract:

    One of the critical and costly components in digital cellular communication systems is the RF power amplifier. Theoretically, one of the main concerns in an RF power amplifier design is the nonlinear effect of the amplifier. Quantitatively, no explicit relationship or expression currently exists between the out-of-band emission level and the nonlinearity description related to the third-order Intercept Point (IP/sub 3/). Further, in experiments and analysis, it was discovered that, in some situations, using IP/sub 3/ only is not accurate enough to describe the spectrum regrowth, especially when the fifth-order Intercept Point (IP/sub 5/) is relatively high compared to the third-order intermodulation. In this article, we analyze the nonlinear effect of an RF power amplifier in CDMA (IS-95 standard), TDMA (IS-54 standard) and Motorola iDEN system, give an expressions of the estimation of the out-of-band emission levels for each system expression by power spectrum respectively, in terms of the IP/sub 3/ and IP/sub 5/, as well as the power level of the signal. This result will be useful in the design of RF power amplifier for these wireless communication systems.

  • Linear RF power amplifier design for wireless signals: a spectrum analysis approach
    2003 IEEE International Conference on Acoustics Speech and Signal Processing 2003. Proceedings. (ICASSP '03)., 2003
    Co-Authors: Heng Xiao, Qiang Wu, Fu Li
    Abstract:

    One of the critical and costly components in digital cellular communication systems is the RF power amplifier. Theoretically, one of the main concerns in an RF power amplifier design is the nonlinear effect of the amplifier. Quantitatively, no explicit relationship or expression currently exists between the out-of-band emission level and the nonlinearity description related to the third-order Intercept Point (IP/sub 3/). Further, in experiments and analysis, it was discovered that, in some situations, using IP/sub 3/ only is not accurate enough to describe the spectrum regrowth, especially when the fifth-order Intercept Point (IP/sub 5/) is relatively high compared to the third-order intermodulation. In this article, we analyze the nonlinear effect of an RF power amplifier in CDMA (IS-95 Standard), TDMA (IS-54 Standard) and MIRS M-16-QAM (Motorola MIRS standard) system, give expressions of the estimation of the out-of-band emission levels for each system expressed by power spectrum respectively, in terms of the IP/sub 3/ and the IP/sub 5/ as well as the power level of the signal. This result will be useful in the design of RF power amplifier for these wireless communication systems.

  • Nonlinear distortion analysis of RF power amplifiers for wireless signals
    6th International Conference on Signal Processing 2002., 2002
    Co-Authors: Heng Xiao, Qiang Wu, Fu Li
    Abstract:

    One of the critical and costly components in digital cellular communication systems is the RF power amplifier. Theoretically, one of the main concerns in an RF power amplifier design is the nonlinear effect of the amplifier. Quantitatively, no explicit relationship or expression currently exists between the out-of-band emission level and the nonlinearity description related to the third-order Intercept Point (IP/sub 3/). Further, in experiments and analysis, it was discovered that, in some situations, using IP/sub 3/ only is not accurate enough to describe the spectrum regrowth, especially when the fifth-order Intercept Point (IP/sub 5/) is relatively high compared to the third-order intermodulation. We analyze the nonlinear effect of an RF power amplifier in CDMA (IS-95 Standard), TDMA (IS-54 Standard) and MIRS M-16-QAM (Motorola integrated radio system standard) systems, give expressions for the estimation of the out-of-band emission levels for each system expressed by power spectrum, in terms of the IP/sub 3/ and the IP/sub 5/, as well as the power level of the signal. This result may be useful in the design of RF power amplifiers for these wireless communication systems.

  • Spectrum design of RF power amplifier for wireless communication systems
    IEEE Transactions on Consumer Electronics, 2002
    Co-Authors: Heng Xiao, Qiang Wu, Fu Li
    Abstract:

    One of the critical and costly components in digital cellular communication systems is the RF power amplifier. Theoretically, one of the main concerns in an RF power amplifier design is the nonlinear effect of the amplifier. Quantitatively, no explicit relationship or expression currently exists between the out-of-band emission level and the nonlinearity description related to the third-order Intercept Point (IP/sub 3/). Further, in experiments and analysis, it was discovered that, in some situations, using IP/sub 3/ only is not accurate enough to describe the spectrum regrowth, especially when the fifth-order Intercept Point (IP/sub 5/) is relatively high compared to the third-order intermodulation. In this article, we analyze the nonlinear effect of an RF power amplifier in CDMA (IS-95 standard), TDMA (IS-54 standard) and MIRS M-16-QAM (Motorola MIRS standard) system, give an expressions of the estimation of the out-of-band emission levels for each system expressed by power spectrum respectively, in terms of the IP/sub 3/ and the IP/sub 5/, as well as the power level of the signal. This result will be useful in the design of RF power amplifier for these wireless communication systems.

Heng Xiao - One of the best experts on this subject based on the ideXlab platform.

  • Spectrum analysis of nonlinear distortion of RF power amplifiers for wireless signals
    International Conference on Communication Technology Proceedings 2003. ICCT 2003., 2003
    Co-Authors: Heng Xiao, Qiang Wu, Fu Li
    Abstract:

    One of the critical and costly components in digital cellular communication systems is the RF power amplifier. Theoretically, one of the main concerns in an RF power amplifier design is the nonlinear effect of the amplifier. Quantitatively, no explicit relationship or expression currently exists between the out-of-band emission level and the nonlinearity description related to the third-order Intercept Point (IP/sub 3/). Further, in experiments and analysis, it was discovered that, in some situations, using IP/sub 3/ only is not accurate enough to describe the spectrum regrowth, especially when the fifth-order Intercept Point (IP/sub 5/) is relatively high compared to the third-order intermodulation. In this article, we analyze the nonlinear effect of an RF power amplifier in CDMA (IS-95 standard), TDMA (IS-54 standard) and Motorola iDEN system, give an expressions of the estimation of the out-of-band emission levels for each system expression by power spectrum respectively, in terms of the IP/sub 3/ and IP/sub 5/, as well as the power level of the signal. This result will be useful in the design of RF power amplifier for these wireless communication systems.

  • Linear RF power amplifier design for wireless signals: a spectrum analysis approach
    2003 IEEE International Conference on Acoustics Speech and Signal Processing 2003. Proceedings. (ICASSP '03)., 2003
    Co-Authors: Heng Xiao, Qiang Wu, Fu Li
    Abstract:

    One of the critical and costly components in digital cellular communication systems is the RF power amplifier. Theoretically, one of the main concerns in an RF power amplifier design is the nonlinear effect of the amplifier. Quantitatively, no explicit relationship or expression currently exists between the out-of-band emission level and the nonlinearity description related to the third-order Intercept Point (IP/sub 3/). Further, in experiments and analysis, it was discovered that, in some situations, using IP/sub 3/ only is not accurate enough to describe the spectrum regrowth, especially when the fifth-order Intercept Point (IP/sub 5/) is relatively high compared to the third-order intermodulation. In this article, we analyze the nonlinear effect of an RF power amplifier in CDMA (IS-95 Standard), TDMA (IS-54 Standard) and MIRS M-16-QAM (Motorola MIRS standard) system, give expressions of the estimation of the out-of-band emission levels for each system expressed by power spectrum respectively, in terms of the IP/sub 3/ and the IP/sub 5/ as well as the power level of the signal. This result will be useful in the design of RF power amplifier for these wireless communication systems.

  • Nonlinear distortion analysis of RF power amplifiers for wireless signals
    6th International Conference on Signal Processing 2002., 2002
    Co-Authors: Heng Xiao, Qiang Wu, Fu Li
    Abstract:

    One of the critical and costly components in digital cellular communication systems is the RF power amplifier. Theoretically, one of the main concerns in an RF power amplifier design is the nonlinear effect of the amplifier. Quantitatively, no explicit relationship or expression currently exists between the out-of-band emission level and the nonlinearity description related to the third-order Intercept Point (IP/sub 3/). Further, in experiments and analysis, it was discovered that, in some situations, using IP/sub 3/ only is not accurate enough to describe the spectrum regrowth, especially when the fifth-order Intercept Point (IP/sub 5/) is relatively high compared to the third-order intermodulation. We analyze the nonlinear effect of an RF power amplifier in CDMA (IS-95 Standard), TDMA (IS-54 Standard) and MIRS M-16-QAM (Motorola integrated radio system standard) systems, give expressions for the estimation of the out-of-band emission levels for each system expressed by power spectrum, in terms of the IP/sub 3/ and the IP/sub 5/, as well as the power level of the signal. This result may be useful in the design of RF power amplifiers for these wireless communication systems.

  • Spectrum design of RF power amplifier for wireless communication systems
    IEEE Transactions on Consumer Electronics, 2002
    Co-Authors: Heng Xiao, Qiang Wu, Fu Li
    Abstract:

    One of the critical and costly components in digital cellular communication systems is the RF power amplifier. Theoretically, one of the main concerns in an RF power amplifier design is the nonlinear effect of the amplifier. Quantitatively, no explicit relationship or expression currently exists between the out-of-band emission level and the nonlinearity description related to the third-order Intercept Point (IP/sub 3/). Further, in experiments and analysis, it was discovered that, in some situations, using IP/sub 3/ only is not accurate enough to describe the spectrum regrowth, especially when the fifth-order Intercept Point (IP/sub 5/) is relatively high compared to the third-order intermodulation. In this article, we analyze the nonlinear effect of an RF power amplifier in CDMA (IS-95 standard), TDMA (IS-54 standard) and MIRS M-16-QAM (Motorola MIRS standard) system, give an expressions of the estimation of the out-of-band emission levels for each system expressed by power spectrum respectively, in terms of the IP/sub 3/ and the IP/sub 5/, as well as the power level of the signal. This result will be useful in the design of RF power amplifier for these wireless communication systems.

  • Linear RF power amplifier design for TDMA signals: a spectrum analysis approach
    2001 IEEE International Conference on Acoustics Speech and Signal Processing. Proceedings (Cat. No.01CH37221), 2001
    Co-Authors: Heng Xiao, Qiang Wu, Fu Li
    Abstract:

    One of the critical and costly components in digital cellular communication systems is the RF power amplifier. Theoretically, one of the main concerns in an RF power amplifier design is the nonlinear effect of the amplifier. Quantitatively, so far, no explicit relationship or expression currently exists between the out-of-band emission level and the nonlinearity description related to the third-order Intercept Point ( IP/sub 3/). Further, in experiments and analysis, it was discovered that, in some situations, using IP/sub 3/ only is not accurate enough to describe the spectrum regrowth, especially when the fifth-order Intercept Point ( IP/sub 5/) is relatively significant compared to the third-order intermodulation. We analyze the nonlinear effect of an RE power amplifier in a TDMA (IS-54 standard) system, give an expression of the estimation of the out-of-band emission levels for a TDMA power spectrum in terms of the IP/sub 3/ and the IP/sub 5/, as well as the power level of the signal. This result will be useful in the design of an RF power amplifier for a TDMA wireless system.

D C Scott - One of the best experts on this subject based on the ideXlab platform.

  • behaviors of the third order Intercept Point for p i n waveguide photodiodes
    Optics Express, 2009
    Co-Authors: M N Draa, D C Scott, W S C Chang, Jeffrey Bloch, Nong Chen, Steven Bo Chen, Paul K L Yu
    Abstract:

    Waveguide PIN photodiodes with different absorber thicknesses and lengths were fabricated and characterized for linearity. Device A has a thicker absorber and shorter length, resulting in a bandwidth of 20GHz while device B reduces the absorber by half while maintaining the intrinsic layer thickness and almost doubles the length, resulting in a smaller optical overlap factor and a bandwidth of 10GHz. Device B shows a significant enhancement in OIP3 with a record high maximum value for a PIN waveguide photodiode of 42.4dBm at 28mA and -4V bias compared to device A which has a maximum OIP3 of 32.7dBm at 10mA and -4V bias. The increased linearity in device B is attributed to the reduction in optical overlap factor and increase in device length resulting in an easing of the front facet photocurrent density and overall device heating. The DC saturation Points are about 75mA and >160mA for device A and B at -2V bias.

  • frequency behaviors of third order Intercept Point for a waveguide photodiode using three laser two tone setup
    Lasers and Electro-Optics Society Meeting, 2008
    Co-Authors: M N Draa, D C Scott, W S C Chang, Paul K L Yu
    Abstract:

    A three laser two tone setup removes unwanted nonlinearities from the third order Intercept Point (IP3) measurement. A high frequency photodetector with an IP3 upwards of 30 dBm will be analyzed up to 18 GHz using the new setup and with the circuit model used in Jiang (2000).

  • the frequency behavior of the third order Intercept Point in a waveguide photodiode
    IEEE Photonics Technology Letters, 2000
    Co-Authors: Hao Jiang, D C Scott, Dongsoo Shin, G L Li, T A Vang, Paul K L Yu
    Abstract:

    In Hayes's (1993) and Williams's (1996) analyses, the photodiode nonlinearity is attributed to the space charge screening effect. In this paper, the third-order intermodulation distortions of a high frequency, large optical cavity p-i-n waveguide photodiode are characterized up to 18 GHz using a two-tone measurement. At high bias voltage, the third-order Intercept Point (IP3) of the waveguide photodiode is constant at low frequency and /spl sim/f/sup -3/ at high frequency. This closely agrees with our model, which is based upon variation of the photodiode impedance. The measured IP3 of the same device at low bias voltages indicates the contribution of space charge screening under low bias voltage or severe saturation.

J C Campbell - One of the best experts on this subject based on the ideXlab platform.