Gregor Lasser’s research while affiliated with Chalmers University of Technology and other places

... Graphene-based RIS [36] is commonly used in the photonics field, which provides a unique proponent to control signals. Finally, diode-based [37,38] can use the propensities of diodes to switch elements on and off, effectively controlling the surface. Following this analysis and comparison, we use diodes as a control mechanism for mm-wave phase control in our RIS. ...

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A Dumbbell Shape Reconfigurable Intelligent Surface for mm-wave 5G Application

... The ocean is a treasury of resources vital to human survival and the second most significant strategic space after land. The progress of intelligent control [1], numerical simulation [2], information fusion [3], data mining [4], parameter optimization [5], virtual reality [6], artificial intelligence [7], high-end chips [8] and large-scale integrated circuits [9] has also brought about remarkable breakthroughs in the technologies of intelligent underwater vehicles. Intelligent underwater vehicles are applicable to operations in harsh environments which divers and equipment have difficulty accessing, such as during deep-sea resource exploration [10], submarine oil and gas pipeline inspection [11], dam exploration [12], aircraft or shipwreck salvage [13], submarine cable maintenance [14] and submarine cable laying [15], etc. ...

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Research on the Influencing Factors of AUV Hovering Control in Null-Speed State

... Behavior of the 3rd order intermodulation prducts (IM3) has been analyzed in radiation [16], but the effect of load-pull has been ignored. Beam-steering is usually not performed in simulations which take load-pull into account [17]. ...

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Over-the-Air Suppression of Third-Order Intermodulation in a Two-Beam Steered Amplifier-Antenna Array

... The implemented tunable notch hybrid circuit does not have any gain and would thus increase the noise figure of the receiver as with any lossy filter. However, since the delay lines are implemented in a MMIC, gain stages can easily be integrated as demonstrated in a GaAs MMIC at X-band in Ref. [37], which improves noise in the figure. This X-band GaAs MMIC is fully integrated with Lange couplers used for the input power divider and output power combiner on chip. ...

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Linear broadband interference suppression circuit based on GaN monolithic microwave integrated circuits

... However, the absence of a standardized NPR measurement methodology [11], coupled with insufficient details in existing characterizations, complicates the critical task of comparing linearity performance among DPAs designed for satellite applications. Many studies in the field present NPR results without explicitly specifying all crucial test conditions such as signal statistics, instantaneous bandwidth (IBM) of the test signals, and the waveform characteristics of the baseband signal [8], [12], [13], [14], [15]. This lack of specificity undermines the ability to confidently define and achieve target NPR performance levels, as these results are significantly influenced by the test conditions themselves [16]. ...

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Design and Extensive NPR Characterization of a Highly Linear SatCom GaN MMIC Doherty PA

... For frequencies above 1 MHz, diplexer JAWS circuits are used to better match the output impedance to 50 X. 30 Diplexers terminate the low-impedance of a long JJ array, thereby reducing on-chip signal reflections and standing waves when transmitting higher-frequency waveforms from the cryogenic JAWS to a room-temperature device under test (DUT). An integrated superconducting diplexer is implemented at the JJ array output of the Very-High-Frequency-band JAWS (VHF-JAWS), which NIST is developing as a quantum-based source for RF power calibrations. ...

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AC metrology applications of the Josephson effect

... Instead, we measure the magnitude of the desired waveform and the integrated in-band noise power. 39,40 A consistently missing or extra pulse in the pattern is equivalent to adding a frequency comb to the spectrum of the calculated pattern, with the phase of the comb frequencies determined by the location of the missing or extra pulse in the pattern. The effect on the magnitude of a single-frequency waveform, therefore, depends on the phase of that comb line, but the appearance of comb frequencies in the surrounding bandwidth will increase the total in-band noise power. ...

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AC metrology applications of the Josephson effect

... The proposed technique is related to our previous frequency-reconfigurable PA architecture in [21], but uses fixed matching networks instead of switch-reconfigurable networks in order to avoid the insertion losses and complexity associated with switches. The theory discussion in this paper addresses the conditions under which the switch-less approach is possible. ...

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C/Ka Concurrent Dual-Band GaN MMIC Based on Shorted Quarter-Wavelength Line Topology

... To evaluate the stability of the proposed LNA, the standard strategy including the Barkhausen criterion and stable factors k and µ should be simulated [32], [53], and [54]. The loop gain simulation is used for the input nodes of the first and second stages [32]. ...

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A Compact 1.0-12.5 GHz LNA MMIC with 1.5-dB NF Based on Multiple Resistive Feedback in 0.15-µm GaAs pHEMT Technology

... Due to the large footprint of the ferrite-based non-reciprocal components, miniaturization concepts that eliminate the need for magnetic biasing using: 1) transistors [30], [31], [32], [33], [34], [35], [36]; 2) self-biased materials [37], [38], [39]; or 3) spatiotemporal modulation (STM) [40], [41], [42], [43], [44], [45], [46] are increasingly being explored. Integrated transistor-based designs [33], [34] are among the most popular design approaches. ...

Reference:

Ferrite-Based Multiport Circulators With RF Co-Designed Bandpass Filtering Capabilities