Polar modulator for multi-mode cell phones

Sander, Wendell B.; Schell, S.V.; Sander, B.L.

doi:10.1109/cicc.2003.1249436

Cited by 44 publications

(23 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The easiest way to reduce the feedforward current is to reduce the supply voltage of the driver stage as well [15]. However, such an approach will also cause the linearity of the amplifier to deteriorate and will reduce the efficiency of the switching amplifier.…”

Section: Feedforwardmentioning

confidence: 99%

“…As such, predistortion is frequently applied, not only in research, but also in commercially available products [15].…”

Section: Predistortionmentioning

confidence: 99%

“…An example of such a system is given in [15]. The architecture uses both AM-AM and AM-PM predistortion to achieve the required linearity over the entire output power range.…”

Section: Architectural Improvementsmentioning

confidence: 99%

See 2 more Smart Citations

CMOS RF Power Amplifiers for Mobile Communications

Reynaert

2010

Multi‐Mode/Multi‐Band RF Transceivers for Wireless Communications

View full text Add to dashboard Cite

Section: Feedforwardmentioning

confidence: 99%

“…As such, predistortion is frequently applied, not only in research, but also in commercially available products [15].…”

Section: Predistortionmentioning

confidence: 99%

See 1 more Smart Citation

CMOS RF Power Amplifiers for Mobile Communications

Reynaert

2010

Multi‐Mode/Multi‐Band RF Transceivers for Wireless Communications

View full text Add to dashboard Cite

“…Recently, some designs based on polarization are researched and developed [24][25][26][27][28][29][30][31], such as polar modulation in the enhance data rates for global evolution (EDGE) system focusing on overcoming the problems of high power consumption, low efficiency, excessive heat and short battery life due to the requirement of linear power amplifier when adopting 3π 8 -8PSK modulation technique. In the exiting polar modulation introduced into EDGE, the orthogonal output from I/Q channels is transformed into the polarization format, i.e., one is the amplitude component and the other is the phase component before being sent to the transmitter, as shown in Figure 1.…”

Section: Introductionmentioning

confidence: 99%

Polarization division multiple access with polarization modulation for LOS wireless communications

Cao

Zhang

Jin

2011

J Wireless Com Network

View full text Add to dashboard Cite

In this paper, we discuss a potential multiple access and modulation scheme based on polarized states (PS) of electromagnetic (EM) waves for line-of-sight (LOS) communications. The proposed scheme is theoretic different from the existing polar modulation for EDGE and WCDMA systems. We propose the detailed bit representation (modulation) and multiple access scheme using PS. Because of the inflexibility of polarization information in the time and frequency domains, as well as independence of frequency and space, the polarization information can be used independently for wireless communications, i.e., another independent resource domain that can be utilized. Due to the independence between the PS and the specific features of signals (such as waveform, bandwidth and data rate), the discussed polarization division multiple access (PDMA) and polarization modulation (PM) are expected to improve the spectrum utilization effectively. It is proved that the polarization filtering technique can be adopted in the PDMA-PM wireless communications to separate the multiuser signals and demodulate the bit information representing by PS for desired user. Some theoretical analysis is done to demonstrate the feasibility of the proposed scheme, and the simulation results are made to evaluate the performance of the suggested system.

show abstract

“…A common implementation of the polar modulation transmitter [29][30][31][32], shown in Fig. 2.2, decomposes the baseband signal into amplitude (v env (t)) and phase (φ(t)) components.…”

Section: Polar Modulationmentioning

confidence: 99%

Pulse-Width Modulated RF Transmitters

Haque¹

View full text Add to dashboard Cite

To my mother, father, and uncle (mamoo), AbstractThe market for wireless portable devices has grown significantly over the recent years. Wireless devices with ever-increased functionality require high rate data transmission and reduced costs. High data rate is achieved through communication standards such as LTE and WLAN, which generate signals with high peak-to-average-power ratio (PAPR), hence requiring a power amplifier (PA) that can handle a large dynamic range signal. To keep the costs low, modern CMOS processes allow the integration of the digital, analog and radio functions on to a single chip. However, the design of PAs with large dynamic range and high efficiency is challenging due to the low voltage headroom.To prolong the battery life, the PAs have to be power-efficient as they consume a sizable percentage of the total power. For LTE and WLAN, traditional transmitters operate the PA at back-off power, below their peak efficiency, whereas pulse-width modulation (PWM) transmitters use the PA at their peak power, resulting in a higher efficiency. PWM transmitters can use both linear and SMPAs where the latter are more power efficient and easy to implement in nanometer CMOS. The PWM transmitters have a higher efficiency but suffer from image and aliasing distortion, resulting in a lower dynamic range, amplitude and phase resolution.This thesis studies several new transmitter architectures to improve the dynamic range, amplitude and phase resolution of PWM transmitters with relaxed filtering requirements. The architectures are suited for fully integrated CMOS solutions, in particular for portable applications.The first transmitter (MAF-PWMT) eliminates aliasing and image distortions while allowing the use of SMPAs by combining RF-PWM and band-limited PWM. The transmitter can be implemented using all-digital techniques and exhibits an improved linearity and spectral performance. The approach is validated using a Class-D PA based transmitter where an improvement of 10.2 dB in the dynamic range compared to a PWM transmitter for a 1.4 MHz of LTE signal is achieved.The second transmitter (AC-PWMT) compensates for aliasing distortion by combining PWM and outphasing. It can be used with switch-mode PAs (SMPAs) or linear PAs at peak power. The proposed transmitter shows better linearity, improved spectral performance and increased dynamic range as it does not suffer from AM-AM distortion of the PAs and aliasing distortion due to digital PWM. The idea is validated using push-pull PAs and the proposed transmitter shows an improvement of 9 dB in the dynamic range as compared v vi Abstract to a PWM transmitter using digital pulse-width modulation for a 1.4 MHz LTE signal.The third transmitter (MD-PWMT) is an all-digital implementation of the second transmitter. The PWM is implemented using a Field Programmable Gate Array (FPGA) core, and outphasing is implemented as pulse-position modulation using FPGA transceivers, which drive two class-D PAs. The digital implementation offers the flexibility to adapt the transmitter...

show abstract

Polar modulator for multi-mode cell phones

Cited by 44 publications

References 1 publication

CMOS RF Power Amplifiers for Mobile Communications

CMOS RF Power Amplifiers for Mobile Communications

Polarization division multiple access with polarization modulation for LOS wireless communications

Pulse-Width Modulated RF Transmitters

Contact Info

Product

Resources

About