The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The pulse-modulated polar transmitters have been developed to answer the call for the need of linear and efficient power amplification for wireless applications. The envelope of the modulated RF signal is converted into the pulse train by means of pulse width modulation or delta-sigma modulation. The power amplification of the pulse train can be performed by the highly efficient power amplifiers without...
Radio-Frequency Identification (RFID) has become a technology segment that growth rapidly in data collecting industry and automatic identification. One of the most important part of RFID system is power amplifier that enable power transfer between reader and transponder for identification purpose. This research is proposed power amplifier class E for RFID application at frequency of 13.56 MHz. It...
A 100W CW UHF band SSPA has been developed and qualified for communication payloads in geostationary satellites. The design is based MOSFET devices in push-pull configuration. The Solid State Power amplifier (SSPA) is capable of operating in multi-carrier operation with 3rd Order Inter-Modulation Distortion (IMD) better than 21dBc. The SSPA provides 100W output power with DC power consumption of 320...
This paper identifies the need of satellite operators for in-orbit flexibility. It also examines the various advantages of flexible dual LCTWTA used onboard communication satellites, as well as the areas that need to be considered by LCTWTA manufacturers for this new technology to remain attractive.
The theoretical bandwidth constrains of conventional symmetric and asymmetric Doherty amplifiers are evaluated and compared to those of the recently introduced novel three and 4-way Doherty amplifier configurations. Performance trends are identified and backed-up by practical results.
This paper introduces a novel technique for simultaneous linearity and efficiency enhancement of class-D amplifiers by combining a low frequency sinusoid, known as dither, with a bandpass signal. The proposed technique improves the linearity due to dither averaging effect, and power efficiency, due to the reduction of reactive loss. The feasibility of the idea is verified through realization and measurement...
This paper introduces a novel technique for simultaneous linearity and efficiency enhancement of class-D amplifiers by combining a low frequency sinusoid, known as dither, with a bandpass signal. The proposed technique improves the linearity due to dither averaging effect, and power efficiency, due to the reduction of reactive loss. The feasibility of the idea is verified through realization and measurement...
This paper introduces a novel technique for simultaneous linearity and efficiency enhancement of class-D amplifiers by combining a low frequency sinusoid, known as dither, with a bandpass signal. The proposed technique improves the linearity due to dither averaging effect, and power efficiency, due to the reduction of reactive loss. The feasibility of the idea is verified through realization and measurement...
A CMOS transmitter frontend integrated circuit suitable for 24-GHz frequency-modulated continuous-wave (FMCW) radar applications is presented in this paper. With a transformer-based power-combining technique and pseudo-differential class-AB power amplifiers (PAs), the proposed circuit exhibits enhanced output power and efficiency at a nominal supply voltage. In addition, a voltage-controlled oscillator...
Combination of a band-pass signal with a low frequency sinusoid signal, also known as dithering, will linearize the performance and reduce the reactive power loss of class D amplifiers. The expectations are verified through realization and measurement of a 2 watt current mode LDMOS class D amplifier operating at 2.014 GHz. The drain efficiency is enhanced from 55 to 59 percent, while giving ACPR levels...
This paper shows a Class-E RF power amplifier designed to obtain a flat-top transistor-voltage waveform whose peak value is 81% of the peak value of the voltage of a “Classical” Class-E amplifier.
This paper presents a highly efficient GaN Doherty power amplifier (DPA) with 100 MHz signal bandwidth and 40 dBm average output power for 3.5 GHz LTE-Advanced application. The carrier and peaking amplifiers are fabricated using 60-W GaN HEMT and implemented with unequal saturation power (Psat) in order to maintain high efficiency at large backed-off power (BOP). The highest drain efficiency (DE)...
More than a brief introduction to the linear technology in the field of wireless communications and radio and television within the wide application of linearization techniques to achieve a certain degree of difficulty, but the benefits of the system is to improve efficiency and save the volume and reduce costs. For each type of system characteristics and requirements of appropriate technology should...
We have demonstrated 8.5–11.5 GHz class-E MMIC high-power amplifiers (HPAs) with a peak power-added-efficiency (PAE) of 61% and drain efficiency (DE) of 70% with an output power of 3.7 W in a continuous-mode operation. At 5 W output power, PAE and DE of 58% and 67% are measured, respectively, which implies MMIC power density of 5 W/mm at Vds = 30 V. The peak gain is 11 dB, with an associated gain...
This paper proposes a harmonic matching network with minimum loss based on precise harmonic load pull measurement to enhance the efficiency and gain for harmonic matched power amplifiers. In this method, the number of stubs for harmonic matching network was reduced in order to minimize the loss and increase the efficiency. A power amplifier with a GaN transistor at 2.45 GHz frequency was designed...
Handset RF power amplifiers modules (PAM) are often operated into mismatched antenna loads due to reflections from nearby objects. We present experimental results comparing the performance of a GaAs HBT PAM operating in fixed supply and Envelope Tracking (ET) modes under high load mismatch conditions. For a load mismatch voltage standing wave ratio (VSWR) of 3:1 at the PAM output plane, the maximum...
A high efficiency wideband code-division multiple access (W-CDMA) base station amplifier using LDMOS is presented in the 900MHz to 980MHz band. LDMOS has widely demonstrated its ability to work efficiently within Doherty structure at attractive cost, and it is shown that it can also be used together a drain modulated system. The transistor is in inverted class F, and in a polar transmitter topology:...
A class-E Chireix outphasing power amplifier is presented that enables high efficiency across a wide power back-off range and RF bandwidth. In this design the Chireix compensation elements and class-E loading conditions are provided by an asymmetric coupled-line power combiner. The class-E operated GaN HEMT switches are driven by high-speed, high-voltage CMOS drivers, implemented in a standard 65nm...
A Ku-band 60W GaN power amplifier is presented. To obtain the high efficiency, new matching circuit topology to control the reflection phase at the 2nd harmonic frequency (2fo) is applied to the power amplifier. The measured power added efficiency (PAE) of 44.9% with the output power of 47.9dBm (62.2W) is obtained in the 15GHz-band. To the best of our knowledge, the PAE is the highest of the Ku-band...
Based on bipolar junction transistor (BJT) modeling the theoretical analysis of biasing effect on improvement of linearity and efficiency of RF linear power amplifier (LPA) are introduced, according to these analysis and by using matlab curve fitting toolbox an analytical model for improvement of linearity and efficiency of RF linear power amplifiers (PAs) is introduced. This model simplifies the...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.