| 1. |
- Gevorgian, Spartak, 1948, et al.
(författare)
-
DC field induced antiferroelectric phase transition in bulk, single crystal strontium titanate
- 2001
-
Ingår i: Integrated Ferroelectrics. - : Informa UK Limited. - 1058-4587 .- 1607-8489. ; 33:1-4, s. 323-329
-
Tidskriftsartikel (refereegranskat)abstract
- Dielectric hysteresis in bulk, single crystal SrTiO3 (STO) with YBa2Cu3O7. x(YBCO) electrodes is studied experimentally at 77K. In contrast with previously reported experiments [1], [2] the antiferroelectric phase transition is observed at higher temperature (i.e. 77K). The phase transition is observed where the crystal is cooled either with short circuited or with open circuited electrodes. The phase transition does not result in detectable changes in the microwave losses.
|
|
| 2. |
|
|
| 3. |
- Carlsson, Erik F., 1968, et al.
(författare)
-
Arrangement and method relating to filtering of signals
- 2000
-
Patent (övrigt vetenskapligt/konstnärligt)abstract
- A superconducting notch or band reject filter arrangement includes a superconducting dielectric resonator and a waveguide arrangement including a microstrip line to which the resonator is connected. The resonator is a parallel-plate resonator with a chip of a non-linear dielectric material device on which superconductors are arranged and the waveguide arrangement includes a contact device or a coupling device, the resonator being connected to the contact device of the waveguide arrangement in such a way that electric contact is provided, and the filter arrangement is frequency tuneable. Through the arrangement, the insertion losses are low
|
|
| 4. |
- Eriksson, Anders, 1971, et al.
(författare)
-
Mode chart of electrically thin parallel-plate circular resonators
- 2001
-
Ingår i: IEE Proceedings: Microwaves, Antennas and Propagation. - : Institution of Engineering and Technology (IET). - 1350-2417 .- 1359-706X. ; 148:1, s. 51 - 55
-
Tidskriftsartikel (refereegranskat)abstract
- Modes in electrically thin circular parallel-plate resonators are discussed in detail. It is shown that the widely used mode indices (found from the field solutions) do not indicate the radial numbers of the field maximums in a straightforward manner. The diameter of the disc, not the radius, accommodates integer numbers of the field maximums (antinodes). These diametrical numbers are expressed in terms of radial mode indices. Emphasis is placed on the first axially symmetric mode TM020, which was incorrectly regarded as TM010 in the past. Some applications of the mode chart, including interpretation of experimental observations, are also discussed. Comparison is made with microstrip and annular resonators.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Gevorgian, Spartak, 1948, et al.
(författare)
-
Analytic approximation for open-end capacitance in symmetric coplanar-strip waveguides
- 2001
-
Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 37:20, s. 1226 - 1228
-
Tidskriftsartikel (refereegranskat)abstract
- Conformal mapping and partial capacitance technique are used to derive simple and accurate closed form approximations for open-end capacitance in a symmetric coplanar-strip waveguide.
|
|
| 8. |
|
|
| 9. |
- Kuylenstierna, Dan, 1976, et al.
(författare)
-
BROADBAND SMALL SIZE BALUN BUILT WITH LUMPED COMPONENTS
- 2003
-
Ingår i: Gigahertz 2003 Proceedings. - 0780383311
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)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/
|
|
| 10. |
- Kuylenstierna, Dan, 1976, et al.
(författare)
-
Design of broad-band lumped-element baluns with inherent impedance transformation
- 2004
-
Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 52:12, s. 2739-45
-
Tidskriftsartikel (refereegranskat)abstract
- This paper reports on a novel lumped balun topology, the second-order lattice balun, with broad-band performance. The design is based on synthetic transmission lines operating as impedance transformers. The characteristic impedance of the synthetic transmission lines may be chosen to obtain inherent impedance transformation. An analytical investigation results in closed formulas for optimum performance over a given bandwidth. It is shown that it is possible to design for equal ripple in amplitude balance and input reflection coefficient. The phase balance is theoretically perfect over the entire bandwidth. The concept is experimentally validated by a 1-GHz prototype fabricated with surface mounted chip components. It exhibits an amplitude balance better than 0.5 dB and a phase balance better than +or-8 degrees over an octave bandwidth. The effective area of the prototype is 7 * 9 mm/sup 2/
|
|
