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| 2. |
- Sjöland, Henrik, et al.
(författare)
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A 100MHz CMOS wideband IF amplifier
- 1998
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Ingår i: IEEE Journal of Solid-State Circuits. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9200. ; 33:4, s. 631-634
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Tidskriftsartikel (refereegranskat)abstract
- When the data rates of communication systems increase, wideband IF amplifiers are needed. It is also possible to use a single wideband intermediate frequency (IF) amplifier for a radio band with several narrow-band channels of varying strengths. The linearity is then critical, if intermodulation products are not to disturb weak channels. We try to find a topology for this new amplifier application, suitable for integration in a standard CMOS process. To get low distortion, we use an output stage with high linearity, which is further linearized by feedback in a double-nested Miller configuration. A 0.8-μm standard CMOS IF amplifier design with low distortion up to 20 MHz is presented.
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| 3. |
- Sjöland, Henrik, et al.
(författare)
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A 160MHz bipolar wideband IF amplifier
- 1998
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Ingår i: IEEE Journal of Solid-State Circuits. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9200. ; 33:10, s. 1555-1558
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Tidskriftsartikel (refereegranskat)abstract
- Wide-band intermediate-frequency (IF) amplifiers are needed when the data rates of communication systems increase. A single wide-band IF amplifier can also be used for a radio band with several narrow-band channels of varying strengths. High linearity is then required if intermodulation products are not to disturb weak channels. We have previously reported a highly linear wide-band IF amplifier in a complementary metal-oxide-semiconductor process. Using a similar topology, an npn-only bipolar amplifier with even higher linearity is now presented. The amplifier is fully differential and operates with a 5 V supply, At 20 MHz, 5 Vpp over a 1 kΩ load, the measured total harmonic distortion is just 9.068%.
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| 4. |
- Sjöland, Henrik, et al.
(författare)
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A novel class AB CMOS power amplifier
- 1997
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Ingår i: Analog Integrated Circuits and Signal Processing. - 0925-1030. ; 12:1, s. 49-58
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Tidskriftsartikel (refereegranskat)
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| 5. |
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| 6. |
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| 7. |
- Sjöland, Henrik
(författare)
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An inductorless 300MHz wideband CMOS power amplifier
- 1999
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Ingår i: Analog Integrated Circuits and Signal Processing. - 0925-1030. ; 21:1, s. 57-65
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Tidskriftsartikel (refereegranskat)abstract
- The power amplifier tends to be one of the most demanding parts to fully integrate when building an entire radio on a CMOS chip. In this paper the design of a fully integrated RF power amplifier without inductors is described. As inductors in CMOS technology are associated with various problems, it is interesting to examine what performance can be achieved without them. An amplifier with an operating band from 60 MHz to 300 MHz (–3 dB) is built in 0.8 m CMOS. A 3 V supply is used. The measured midband power gain is 30 dB with 50 resistive source and load impedance. As linearity is important for many modern modulation schemes, the amplifier is designed to be as linear as possible. The measured third order intercept point is 23 dBm and the 1 dB compression point is 10 dBm, both referred to the output. The output is single ended to avoid an off-chip differential to single ended transformer.
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| 8. |
- Sjöland, Henrik
(författare)
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Design and Analysis of Highly Linear Integrated Wideband Amplifiers
- 1997
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation deals with techniques for designing integrated amplifiers with high linearity. Amplifiers with operating frequencies from Audio to RF have been built. An enhanced feedback configuration, capable of very low distortion, is presented. Also presented is a statistical method for relating the distortion of a wideband signal to the total harmonic distortion (THD) of a single tone. Two fully integrated class AB CMOS audio power amplifiers that are capable of driving 8Ohm loudspeaker loads directly from the chip are presented. Two different topologies are used, both resulting in low distortion and high output voltage swing. The second amplifier operates with supply voltages down to 1.5V. Both amplifiers feature advanced phase compensation strategies to be able to drive loudspeakers with up to 100nF and down to 8Ohm without external components, such as load stabilising networks. Two wideband IF amplifiers are presented. They are fully integrated and have high linearity from DC to 20MHz. Both have differential inputs and outputs. To achieve high linearity, large feedback together with double nested Miller compensation are used, resulting in a high degree of linearisation of the output stage. One of the amplifiers is built in CMOS and the other is built using npn-only bipolar technology. One fully integrated RF power amplifier in 0.8um CMOS without coils is presented. The purpose of this amplifier is to investigate how fast and linear a power amplifier can be made in CMOS, without using coils to resonate with major parasitic capacitances. This investigation is done in order to be able to build fast RF power amplifiers without coils when the speed of the CMOS processes increases in the future. An enhanced feedback scheme, which is the subject to a patent application, is also presented. By connecting a negative impedance to the inverting input of a feedback amplifier, the feedback can be boosted to become infinite at a certain frequency. Thereby the distortion at this frequency can be eliminated completely. The gain of the arrangement is equal to that with an ideal amplifier. Finally a novel method of how to relate the intermodulation distortion of a wideband signal to the total harmonic distortion (THD) of a single tone test is presented. The motivation for this is that the THD, as opposed to the intermodulation distortion of the wideband signal, is easy to measure and use as a design parameter. It is shown how to select both the amplitude and the frequency of the single tone to get the same distortion power as with a wideband signal.
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| 9. |
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| 10. |
- Sjöland, Henrik, et al.
(författare)
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Intermodulation noise realted to THD in dynamic nonlinear wideband amplifiers
- 1998
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Ingår i: IEEE Transactions on Circuits and Systems - 2, Analog and Digital Signal Processing. - 1057-7130. ; 45:7, s. 873-875
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Tidskriftsartikel (refereegranskat)abstract
- In this work it is shown that the power of the intermodulation noise of a wide-band amplifier with dynamic nonlinearities can be estimated by the total harmonic distortion (THD) with a sinusoid input signal of appropriate amplitude and frequency. The THD is, as opposed to the intermodulation noise, easy to measure and use as a design parameter.
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