| 1. |
- Beuerle, Bernhard, 1983-, et al.
(författare)
-
Low-Loss Silicon Micromachined Waveguides Above 100 GHz Utilising Multiple H-plane Splits
- 2018
-
Ingår i: Proceedings of the 48th European Microwave Conference, Madrid, October 1-3, 2018. - : Institute of Electrical and Electronics Engineers (IEEE). - 9782874870514 ; , s. 1041-1044
-
Konferensbidrag (refereegranskat)abstract
- For sub-millimeter and millimeter wave applications rectangular waveguides are an ideal transmission medium. Compared to conventional, metal-milled rectangular waveguides, silicon micromachined waveguides offer a number of advantages. In this paper we present a low-loss silicon micromachined waveguide technology based on a double H-plane split for the frequency bands of 110 – 170 GHz and 220 – 330 GHz. For the upper band a reduced height waveguide is presented, which achieves a loss per unit length of 0.02 – 0.10 dB/mm. This technology has been further adapted to implement a full height waveguide for the lower frequency band of 110 – 170 GHz. The full height waveguide takes advantage of the benefits of the double H-plane split technique to overcome the challenges of fabricating micromachined waveguides at lower frequencies. With measured insertion loss of 0.007 – 0.013 dB/mm, averaging 0.009 dB/mm over the whole band, this technology offers the lowest insertion loss of any D-band waveguide to date. The unloaded Q factor of the D-band waveguide technology is estimated to be in excess of 1600, while a value of 750 has been measured for the reduced height upper band waveguide.
|
|
| 2. |
- Fishler, Dan, et al.
(författare)
-
Supply Modulation of a Linear Doherty Power Amplifier
- 2018
-
Ingår i: 2018 48th European Microwave Conference, EuMC 2018. - 9782874870514 ; , s. 519-522
-
Konferensbidrag (refereegranskat)abstract
- This paper presents a study of supply modulation of a Doherty power amplifier (DPA) designed for linear operation. The symmetrical DPA is designed with Wolfspeed 6-W packaged devices for operation at 3.5 GHz with a peak output power of 42dBm and a peak power-added efficiency (PAE) of 55%. Supply modulation is characterized statically when the main and auxiliary amplifier supply voltages are modulated separately, as well as simultaneously. The DPA is then characterized with 60-MHz LTE-like signals with 6 dB and 10 dB peak-to-average power ratios (PAPR). After digital pre-distortion using an iterative learning control algorithm, the composite PAE for a 10-dB PAPR signal is 38.7%, with mean-square error (NMSE) and ACLR values of 0.3% and -47 dBc.
|
|
| 3. |
- Hassona, Ahmed Adel, 1988, et al.
(författare)
-
Low-cost D-band Waveguide Transition on LCP Substrate
- 2018
-
Ingår i: 48th European Microwave Conference (EuMC). - 9782874870514 ; , s. 1049-1052
-
Konferensbidrag (refereegranskat)abstract
- This work presents a waveguide transition based on a slot radiator implemented on liquid crystal polymer (LCP) substrate. The slot couples the RF signal to a D-band (110–170 GHz) waveguide perpendicular to its plane. The slot is fed using a microstrip line and can be bonded to any monolithic microwave integrated circuit (MMIC). A waveguide split-block that utilizes bed of nails structure is also presented. The structure is used to stop undesired radiation at the interface between the slot and the waveguide opening allowing better coupling between the slot and the waveguide by reducing radiation loss. The transition shows a minimum insertion loss of 2.1 dB and an average of 3.2 dB. The 3-dB bandwidth of the transition covers the frequency range 112 –140 GHz. Another variant of the transition is designed to cover the higher part of the band and shows an average insertion loss of 3.6 dB covering the frequency range 124–154 GHz. The transition presents a simple low-cost technique to interface between standard waveguides and MMICs in millimeter-waves systems.
|
|
| 4. |
- Heunisch, Sebastian, et al.
(författare)
-
Pulse-Distortion Analysis for Millimeter-Wave Time-Domain Material Identification
- 2018
-
Ingår i: 2018 48th European Microwave Conference, EuMC 2018. - 9782874870514 ; , s. 572-575
-
Konferensbidrag (refereegranskat)abstract
- Analyzing the frequency dependent dielectric properties can be used to identify and distinguish materials in biomedical instruments. In the millimeter-wave range, the dielectric properties of biological tissues are mainly determined by their water content. For instance, it has been shown, that cancer cells have a lower water content than healthy skin cells, resulting in a significant dielectric contrast between them. In this work, we analyze the pulse distortion observed in measurements of the millimeter-wave reflection of water and porcine skin. We propose to use the distortion caused by the frequency dependent reflection coefficient at the interface of a material as a feature for identification. Using a simplified model for the reflection coefficient of the material under test, we simulate the distortion caused by the frequency dispersion. In simulation as well as in measurement, we observe different startup transients depending on the dispersion properties of a material under test. The startup behavior can therefore be used as feature, to directly identify dispersive materials in the time domain.
|
|
| 5. |
- Zeng, Xuezhi, 1980, et al.
(författare)
-
Investigation of a Time Domain Microwave System for Biomedical Applications
- 2018
-
Ingår i: 2018 48th European Microwave Conference, EuMC 2018. - 9782874870514 ; , s. 503-506
-
Konferensbidrag (refereegranskat)abstract
- A time domain microwave system completely based on off-the-shelf components is developed for biomedical applications. This work is the investigation of this system for two different type of applications: medical diagnosis and vital sign detection. The results show that the system is accurate enough for most of the measurement scenarios. Both the respiration rate and heartbeat rate are detectable with the system and the success rate of respiration detection is 100% for seventeen tests we have performed.
|
|
