| 21. |
- Kuylenstierna, Dan, 1976, et al.
(författare)
-
Design of broadband lumped element baluns
- 2004
-
Ingår i: 2004 IEEE MTT-S International Microwave Symposium Digest, 6-11 June 2004. - 0780383311 ; Vol.2, s. 899-902
-
Konferensbidrag (refereegranskat)abstract
- This paper reports on a small size broadband lumped element balun suitable for integration in MMICs. The design is an extension of the well known lattice balun, which independent of frequency has 180 degrees phase difference between the output ports, but suffers from a narrow amplitude bandwidth. It is shown how the amplitude bandwidth of the lattice balun may be improved by replacing inductors with low-pass T-sections, and the capacitors with high-pass T-sections. Scalable closed-form design equations for various bandwidths are derived. To validate the concept a prototype operating at 1 GHz has been fabricated with SMT chip components soldered on a PTFE laminate. It exhibits amplitude balance better than +or-0.25 dB and phase balance better than +or-8 degrees , over more than one octave bandwidth. The effective chip-area is 7*9 mm/sup 2/
|
|
| 22. |
- Kuylenstierna, Dan, 1976, et al.
(författare)
-
Ferroelectrically tuneable delay lines
- 2004
-
Ingår i: Conference Proceedings. 34th European Microwave Conference, 12-14 Oct. 2004. ; vol.1, s. 157-60
-
Konferensbidrag (refereegranskat)abstract
- Ferroelectric (Ba/sub 0.25/Sr/sub 0.75/TiO/sub 3/) varactors are integrated on a Si substrate to form compact wideband true-time tuneable delay lines. The delay-line design is of the lumped element approach, implemented as a synthetic coplanar strip (CPS) line. The physical size of the delay lines is 2.0*0.33 mm/sup 2/. Up to 20 GHz, the measured delay time per unit length is approximately constant equal to 40 ps/mm (corresponding to a slow wave factor of 12) and the losses are about 0.049 dB/ps. The tuneability under 30 V DC-bias is 10%
|
|
| 23. |
|
|
| 24. |
- Kuylenstierna, Dan, 1976, et al.
(författare)
-
Ultrawide-band tunable true-time delay lines using ferroelectric varactors
- 2005
-
Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 53:6, pt.2, s. 2164-70
-
Tidskriftsartikel (refereegranskat)abstract
- This paper reports on compact tunable true-time delay lines based on ferroelectric (Ba/sub 0.25/Sr/sub 0.75/TiO/sub 3/) varactors integrated on high-resistivity silicon. The delay lines are based on lumped elements, physically implemented as synthetic coplanar-strip lines. An approximate analytical design procedure, exactly valid for omega to 0, is proposed. The physical size of the fabricated delay lines is 2.0*0.33 mm/sup 2/, including bias pads. Measurements are performed from room temperature (RT) down to 80 K. The measurements reveal ultrawide-band characteristics for both group delay and insertion loss. At RT, the absolute group delay is tau /sub delta /(RT, 0 V) approximately=70 ps with tunability of 20% under 20-V dc bias, the insertion less than 3.5 dB, and the reflection loss better than 12 dB below 20 GHz. At 145 K, the absolute group delay is increased to tau /sub delta /(145 K, 0 V) approximately=100 ps with a tunability of 50% under 20-V applied bias. At 7 GHz, the insertion loss is 3 dB, resulting in figures-of-merit of 0.03 dB/ps and 50 ps/mm. The leakage current at RT is less than 0.1 mu A
|
|
| 25. |
- Nilsson, Emil, et al.
(författare)
-
A new CMOS radio for low power RFID applications
- 2010
-
Ingår i: Proceedings of 2010 IEEE International Conference on RFID-Technology and Applications : June 17-19, 2010 : Dong Fang Hotel, Guangzhou, China.. - Piscataway, N.J. : IEEE Press. - 9781424467006 ; , s. 106-111
-
Konferensbidrag (refereegranskat)abstract
- A novel radio receiver circuit, functioning as a tuned active, detecting antenna, is described. The receiver is suggested to be part of a new radio system with the potential of competing with the range capability of active RFID-tags and, through its low power and long lifetime, with passive RFID-tags. The circuit is outlined and the functionality is verified by simulations and measurements.A 24 MHz discrete prototype showed better than -70 dBm sensitivity and 5 kHz bandwidth, with a power consumption of 102 μW. Simulations of a monolithic implementation were performed at 2.5 GHz. The detector is modeled by using 180 nm CMOS transistors. In simulations the power consumption for the detector is below 125 μW at a sensitivity of -83 dBm and a bandwidth of 9 MHz.Our conclusion is that this novel simple circuit architecture is well suited for monolithic implementation of a low power transceiver.
|
|
| 26. |
- Rafique, Raihan, 1978, et al.
(författare)
-
Miniaturization of superconducting passive filters for on-chip applications
- 2007
-
Ingår i: 11th International Superconducting Electronics Conference, Washington DC, USA, June 10-14, 2007.. ; 11, s. P-V09
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We present techniques to miniaturize superconducting ultra narrowband filters for on-chip applications. The filters are designed for 2 GHz, 5 GHz and 10 GHz operating frequencies. The expected bandwidths of the designed filters are 2-20 MHz. The designs are of 7 stages Chebyshev filters having maximum passband ripples of 0.5 dB. On-chip filters are particularly interesting as they are applicable for monolithic design with the RSFQ circuit aiming qubit applications. One of the designs is a quasi-lumped filter where the effective wave propagation constant has been increased by the addition of lumped components to the superconducting microstrip line (SMSL). Additionally, this design provides the optimum width of an SMSL without violating design rules. The other design consists of distributed and lumped components. The area of the filter is in the range of 1-2 square mm. We present the filter topologies and corresponding experimental results for the frequency response of these on-chip filters designed for Hypres 4.5 kA/cm2 fabrication process.
|
|
| 27. |
- Rafique, Raihan, 1978, et al.
(författare)
-
Miniaturized superconducting microwave filters
- 2008
-
Ingår i: Superconducting Science and technology, press.
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper we present methods for miniaturization of superconducting filters. We consider two designs of 7th order bandpass Chebyshev filters based on lumped elements and a novel quasi-lumped element resonators. In both designs the area of the filters, with a central frequency of 2-5 GHz, is less than 1.2 mm2. Such small filters can be readily integrated on one board for multi-channel microwave control of superconducting qubits. The filters have been experimentally tested and the results are compared with simulations. The miniaturization resulted in parasitic coupling between resonators and within eachresonator that affected primarily stopband and bandwidth increase. The severity of the error depends on the design in particular, and was less prawn when groundplane was used under the inductances of the resonators. The best performance was reached for the quasi-lumped filter with central frequency of 4.5 GHz, quality factor of 100 and 28 dB stopband.
|
|
| 28. |
- Rafique, Raihan, 1978, et al.
(författare)
-
Niobium Tunable Microwave Filter
- 2009
-
Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 57:5, s. 1173-1179
-
Tidskriftsartikel (refereegranskat)abstract
- A superconductor bandpass filter with tunable centralfrequency in the range of 2.1–3.5 GHz has been implementedusing Superconducting Quantum Interference Devices (SQUID).The filter is designed as two pi–network resonators connected by a transmission line. Both resonators have a SQUID inductor with a tuning range of 65–200 pH, controlled by DC current magnetically coupled to the SQUIDs. Over a frequency tunability of 40% from 3.5 to 2.1 GHz, the filter has a corresponding fractional bandwidth of 35% to 27% and a mid-band insertion loss of 0.5–3.0 dB. Due to the presence of active elements, the tunability of the filter depends on the power of the microwave signal. A maximum power of -52dBm corresponds to a frequency tuning range of 15%. Spectral measurements by controlling the central frequency of the filter with variable pulse-width shows that the filter can be tuned at a rate of 120 GHz per us.
|
|
| 29. |
|
|
| 30. |
- Rafique, Raihan, 1978, et al.
(författare)
-
Tunable Impedance Matching Network
- 2008
-
Ingår i: GigaHertz Symposium, March, 2008. ; , s. 15-
-
Konferensbidrag (refereegranskat)abstract
- We present superconducting SQUID based tunableimpedance matching networks designed for highly miniaturized filters. The performance of miniaturized filters is very sensitive to parasitic and fabrication related spread. The presented experimental results show that using tunable impedance matching networks, the degraded performances of these types of filters isimproved.
|
|
