On the Minimum Number of States for Switchable Matching Networks

Firrao, Ettore Lorenzo; Annema, Anne-Johan; Vliet, F.E. van; Nauta, Bram

doi:10.1109/tcsi.2014.2363515

Cited by 9 publications

(25 citation statements)

References 25 publications

(19 reference statements)

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“…Note that the zero order term is the ideal sample point. The effect of DSC is emphasized when we combine equation (2) and the first order term in equation 3resulting in:…”

Section: Delay Spread Cancellationmentioning

confidence: 99%

“…Both effects degrade RF-PA linearity and efficiency. Different handling conditions of the device can significantly change the antenna impedance [1], resulting in reflections that may damage the RF-PA. To compensate for these effects, Adaptive Digital Pre-distortion together with multi-harmonic adaptive matching networks and tunable bias networks can be used, where Adaptive matching networks can be efficiently designed [2]. Currently, implemented compensation techniques utilize temperature sensors, DC-sensors, power detectors [3] or peak detectors [4] to control bias networks or load impedance tuners to compensate for PVT spread and load impedance mismatch.…”

Section: Introductionmentioning

confidence: 99%

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A Delay Spread Cancelling Waveform Characterizer for RF Power Amplifiers

Huiskamp

Annema

Nauta

2018

IEEE Trans. Circuits Syst. II

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A two channel 65 nm CMOS RF-waveform characterizer is presented that enables multi-harmonic Adaptive Matching Networks (AMN) or Adaptive Digital Pre-Distortion (ADPD) in RF-power amplifiers. The characterizer measures the DC component and the first 3 harmonics of RF signals by applying a DFT to 8 (ideally) equally spaced quasi-DC output voltages. Conventionally in these types of systems accuracy is limited by sample timing accuracies, which in our case are mainly due to delay cell mismatch. We introduce a novel way to cancel delay cell mismatch, that significantly increases measurement accuracy at the cost of only a small power and area increase. The RF-waveform characterizer achieves 6.8-bit measurement linearity together with a (clock feedthrough limited) 24 dB SFDR. The measured power consumption for our proof-of-principle demonstrator is 18.6 mW at a maximum input signal frequency of 1.1 GHz under continuous operation.

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“…Note that the zero order term is the ideal sample point. The effect of DSC is emphasized when we combine equation (2) and the first order term in equation 3resulting in:…”

Section: Delay Spread Cancellationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A Delay Spread Cancelling Waveform Characterizer for RF Power Amplifiers

Huiskamp

Annema

Nauta

2018

IEEE Trans. Circuits Syst. II

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“…For example, [9] noted that the hyperbolic distance on the Smith chart is identical to the voltage standing wave ratio, and its applications are in [10] and [11].…”

Section: Introductionmentioning

confidence: 99%

Graphical Representation of the Power Transfer Efficiency of Lumped-Element Circuits Based on Hyperbolic Geometry

Yamada

Ohira

2017

IEEE Trans. Circuits Syst. II

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By adding a passive element to a power source, an inevitable power attenuation caused by the dissipative loss occurs. It is important for some applications to reduce this undesirable attenuation. A representative example of one of these kinds of applications is impedance matching, for which we transform the source's impedance to a different preferable one with passive elements, and the attenuation is to be as low as possible. To give a visible way to design better circuits in such situations, we propose a graphical representation to understand the attenuation from the viewpoint of hyperbolic geometry. We reveal that the attenuation in logarithmic scale (typically, dB or Np) is proportionate to the hyperbolic length of the path representing the movement of the reflection coefficient, and the constant of proportionality is determined by the unloaded Q-factor of the connected elements. Exploiting the result, we can find preferable topologies by using the Smith chart with an intuition. As well as this graphical representation, we also reveal the lower bound of the attenuation in terms of the hyperbolic distance between the two reflection coefficients which we want to match. A new usage of the Smith chart to estimate the loss and its lower bound is given in this study.Index Terms-Smith chart, power efficiency, impedance matching, hyperbolic geometry.

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“…• a tunable matching network ([28] - [60]): the tunable matching network is the matching network that achieves the tuning of the antenna or load. It is made of reactive components (capacitor, inductors, transformers, transmission lines, etc.)…”

Section: Introductionmentioning

confidence: 99%

“…The tunable matching network can be made with continuously tunable components or with switchable components ( [28] - [60]). The component value of the first ones can only be tuned continuously from a minimum value up to a maximum value.…”

Section: Introductionmentioning

confidence: 99%

Automic Antenna Tuners

Firrao¹

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The operating environment of mobile phones fluctuates continuously, due to changing handling conditions and nearby objects. The resulting fluctuations in antenna impedance cause both a decrease in link quality and a higher standing wave ratio, that requires more robust and hence less efficient power amplifier implementations. In this chapter, an automatic antenna tuner system for handheld applications is presented that uses two series reactances combined with three simple RF peak detectors to sense both reactive and real impedance mismatches. The control loop only requires low-frequency electronics which makes it low cost, low power and relatively easy to integrate. Measurements on a demonstrator system show correct behaviour for voltage standingwave ratio up to 10.

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On the Minimum Number of States for Switchable Matching Networks

Cited by 9 publications

References 25 publications

A Delay Spread Cancelling Waveform Characterizer for RF Power Amplifiers

A Delay Spread Cancelling Waveform Characterizer for RF Power Amplifiers

Graphical Representation of the Power Transfer Efficiency of Lumped-Element Circuits Based on Hyperbolic Geometry

Automic Antenna Tuners

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