| 1. |
|
|
| 2. |
- Dahlbäck, Robin, 1985, et al.
(författare)
-
A 340 GHz CW non-linear imaging system
- 2010
-
Ingår i: Infrared Millimeter and Terahertz Waves (IRMMW-THz), 2010. - 9781424466559
-
Konferensbidrag (refereegranskat)abstract
- A CW sub-millimetre wave imaging system is presented. The system operates around 340GHz with a 6.5% relative bandwidth and uses a non-linear imaging algorithm.
|
|
| 3. |
- Dahlbäck, Robin, 1985, et al.
(författare)
-
A compact 128-element Schottky diode grid frequency doubler generating 0.25 W of output power at 183 GHz
- 2017
-
Ingår i: IEEE Microwave and Wireless Components Letters. - 1558-1764 .- 1531-1309. ; 27:2, s. 162-164
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a compact varactor grid frequency doubler encapsulated in a waveguide environment, thus providing single mode (H₁₀) waveguide connection at both input and output. Schottky diodes are used as varactors in this 128-element grid frequency doubler. By packaging the grid and its embedding network together with a stepped waveguide taper on the output, a module measuring 9 mm x 19 mm by 19 mm is created. A peak output power of 0.25 W is produced at 183 GHz with 1.32 W of input power and a corresponding conversion efficiency of 19%. The peak conversion efficiency is 23% at 183 GHz with 666 mW of input power.
|
|
| 4. |
|
|
| 5. |
- Dahlbäck, Robin, 1985, et al.
(författare)
-
A System for THz Imaging of Low-Contrast Targets Using the Born Approximation
- 2012
-
Ingår i: IEEE Transactions on Terahertz Science and Technology. - 2156-342X .- 2156-3446. ; 2:3, s. 361-370
-
Tidskriftsartikel (refereegranskat)abstract
- A THz imaging system, operating at 346 GHz and tailored for implementation of an imaging algorithm based on the Born approximation, is presented. The imaging algorithm provides focusing by compensating for the antenna footprint. This allows for using a more simple antenna system without optical focusing. Several aspects of implementing an imaging algorithm based on the Born approximation in THz imaging are discussed and key system properties are highlighted. The performance of the imaging algorithm is verified by imaging two simple dielectric targets. The results indicate that this approach provides a qualitative indication of the distribution of contrast in the samples complex permittivity and is a potential complement to existing imaging techniques.
|
|
| 6. |
- Dahlbäck, Robin, 1985, et al.
(författare)
-
A Tunable 240–290 GHz Waveguide Enclosed 2-D Grid HBV Frequency Tripler
- 2016
-
Ingår i: IEEE Transactions on Terahertz Science and Technology. - 2156-342X .- 2156-3446. ; 6:3, s. 503-509
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a high-power 240–290 GHz waveguide enclosed two-dimensional (2-D) grid heterostructure barrier varactor (HBV) frequency multiplier. A 35 mW of output power is produced at 247 GHz with an input power of 900 mW. The operational bandwidth is tunable within a 50 GHz span by the use of an input tuner able to adjust the input matching of the 2-D grid HBV frequency multiplier. Tuning is achieved by moving a suspended dielectric slab in the input waveguide.
|
|
| 7. |
- Dahlbäck, Robin, 1985, et al.
(författare)
-
A Waveguide Embedded 250 GHz Frequency-Tripler 2D Array
- 2014
-
Ingår i: Micro-and Millimetre Wave Technology and Techniques Workshop 2014, 25-27 November 2014.
-
Konferensbidrag (refereegranskat)abstract
- This work reports on a 248 GHz HBV (Heterostructure Barrier Varactors)-varactor quasi-optical multiplier array with a maximum output power of 18 mW and a corresponding conversion efficiency of 2 %. The module utilizes a mechanically compact and simple shim system, combining the large array power handling capability with the convenience of waveguide interfaced circuits. At the same time this approach offers excellent power and frequency scalability. The multiplier is based on a 12 by 6 element, 72 in total, planar 2D HBV varactor array. The diodes are fabricated on a three barrier InGaAs/InAlAs material system on InP as carrier substrate. Easch diode consist of two 20um^2 serially connected mesas, yielding a total of six barrier per diode. The HBV diodes are coupled to a uniform dipole array through which the power is coupled in and out. One HBV diode and the corresponding dipole make up a square unit cell with a side of 211 um. The chip measures 2,54 x 1,27 mm^2, fitting inside a standard WR10 waveguide. The complete module consists of three parts, the 2D HBV array, a combined output filter and output matching slab and an input matching slab. A rhombic aperture frequency selective surface is used as the uutput bandpass filter and the quartz filter substrate also serves as a matching slab for the output tone. On the input a piece of InP substrate is used to match the incoming pump signal to the diodes. The components are mounted inside two WR-10 waveguide shims, providing an easy assembly and a modular system. The current version of the multiplier module produces 18 mW at 248 GHz but a significant increase in output power and efficiency is expected with a new output matching network and more pump power. Recent measurement results will be presented together with a detailed discussion regarding the design, pointing out advantages and challenges compared to more traditional approaches to frequency multiplier design in the frequency range. Future improvements and challenges will also be covered.
|
|
| 8. |
- Dahlbäck, Robin, 1985, et al.
(författare)
-
A waveguide embedded 250 GHz quasi-optical frequency-tripler array
- 2014
-
Ingår i: 44th European Microwave Conference, EuMC 2014 - Held as Part of the 17th European Microwave Week, EuMW 2014; Fiera di RomaRome; Italy; 6 October 2014 through 9 October 2014. - 9782874870354 ; , s. 802-805
-
Konferensbidrag (refereegranskat)abstract
- A waveguide embedded 250 GHz HBV-varactor quasi-optical multiplier array is presented. The module utilizes a mechanically compact and simple shim system, combining the large array power handling capability with the convenience of waveguide interfaced circuits. At the same time this approach offers excellent power and frequency scalability. The current tripler prototype produces a non saturated output power of 8 mW at 248 GHz during initial measurements at medium pump power.
|
|
| 9. |
- Dahlbäck, Robin, 1985, et al.
(författare)
-
Compact 340 GHz homodyne transceiver modules for FMWC imaging radar arrays.
- 2016
-
Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. ; 2016-August
-
Konferensbidrag (refereegranskat)abstract
- We present a solution where one single LO chain is used to feed a homodyne FMCW radar transceiver. An InGaAs pHEMT active frequency multiplier MMIC (x8) and a Schottky diode frequency doubler make up the LO chain. The novel Schottky diode based transceiver operates both as a frequency multiplier (x2) and as a sub-harmonic mixer. The modules operate at a center frequency of 340 GHz with a 30 GHz modulation bandwidth. An output power of 0 dBm, an IF noise level of -168 dBm/Hz and a receiver conversion loss of 18 dB is achieved in the band. The form factor of the modules is adapted to build one- or two- dimensional FMCW radar arrays. State of the art system performance is achieved while system complexity, size and cost is significantly reduced.
|
|
| 10. |
- Dahlbäck, Robin, 1985, et al.
(författare)
-
Development of a waveguide integrated sub-millimetre wave spatially power combined HBV multiplier
- 2011
-
Ingår i: 6th ESA Workshop on Millimetre-Wave Technology and Applications and 4th Global Symposium on Millimeter Waves.
-
Konferensbidrag (refereegranskat)abstract
- The development of a sub-millimetre wave, spatially power combined, quasi optical HBV multiplier is presented. Emphasis is placed on key concepts of spatial power combining of frequency multipliers, as well as design challenges. The current state of the design as well as the final goal is further discussed.
|
|
