Performance Assessment of W-Band Radiometers: Direct versus Heterodyne Detections
W-Band radiometers using intermediate frequency down-conversion (super-heterodyne) and direct detection are compared. Both receivers consist of two W-band low noise amplifiers and an 80-to-101 GHz filter, which conforms to the reception frequency band, in the front-end module. The back-end module of...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-09-01
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| Series: | Electronics |
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| Online Access: | https://www.mdpi.com/2079-9292/10/18/2317 |
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| author | Juan Pablo Pascual Beatriz Aja Enrique Villa Jose Vicente Terán Luisa de la Fuente Eduardo Artal |
| author_facet | Juan Pablo Pascual Beatriz Aja Enrique Villa Jose Vicente Terán Luisa de la Fuente Eduardo Artal |
| author_sort | Juan Pablo Pascual |
| collection | DOAJ |
| description | W-Band radiometers using intermediate frequency down-conversion (super-heterodyne) and direct detection are compared. Both receivers consist of two W-band low noise amplifiers and an 80-to-101 GHz filter, which conforms to the reception frequency band, in the front-end module. The back-end module of the first receiver comprises a subharmonic mixer, intermediate frequency (IF) amplification and a square-law detector. For direct detection, a W-Band detector replaces the mixer and the intermediate frequency detection stages. The performance of the whole receivers has been simulated requiring special techniques, based on data from the experimental characterization of each subsystem. In the super-heterodyne implementation a local oscillator at 27.1 GHz (with 8 dBm) with a x3 frequency multiplier is used, exhibiting an overall conversion gain around 48 dB, a noise figure around 4 dB, and an effective bandwidth over 10 GHz. In the direct detection scheme, slightly better noise performance is obtained, with a wider bandwidth, around 20 GHz, since there is no IF bandwidth limitation (~15 GHz), and even using the same 80-to-101 GHz filter, the detector can operate through the whole W-band. Moreover, W-band detector has higher sensitivity than the IF detector, increasing slightly the gain. In both cases, the receiver performance is characterized when a broadband noise input signal is applied. The radiometer characteristics have been obtained working as a total power radiometer and as a Dicke radiometer when an optical chopper is used to modulate the incoming signal. Combining this particular super-heterodyne or direct detection topologies and total power or Dicke modes of operation, four different cases are compared and discussed, achieving similar sensitivities, but better performances in terms of equivalent bandwidth and noise for the direct detection radiometer. It should be noted that this conclusion comes from a particular set of components, which we could consider as typical, but we cannot exclude other conclusions for different components, particularly for different mixers and detectors. |
| first_indexed | 2024-03-10T07:43:34Z |
| format | Article |
| id | doaj.art-77fe4fbd355f49fab42e799776e5a7aa |
| institution | Directory Open Access Journal |
| issn | 2079-9292 |
| language | English |
| last_indexed | 2024-03-10T07:43:34Z |
| publishDate | 2021-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Electronics |
| spelling | doaj.art-77fe4fbd355f49fab42e799776e5a7aa2023-11-22T12:49:10ZengMDPI AGElectronics2079-92922021-09-011018231710.3390/electronics10182317Performance Assessment of W-Band Radiometers: Direct versus Heterodyne DetectionsJuan Pablo Pascual0Beatriz Aja1Enrique Villa2Jose Vicente Terán3Luisa de la Fuente4Eduardo Artal5Departamento de Ingeniería de Comunicaciones, Universidad de Cantabria, Plaza de la Ciencia s/n, 39005 Santander, SpainDepartamento de Ingeniería de Comunicaciones, Universidad de Cantabria, Plaza de la Ciencia s/n, 39005 Santander, SpainIACTEC, Instituto de Astrofísica de Canarias, 38205 La Laguna, SpainERZIA Technologies, 39012 Santander, SpainDepartamento de Ingeniería de Comunicaciones, Universidad de Cantabria, Plaza de la Ciencia s/n, 39005 Santander, SpainDepartamento de Ingeniería de Comunicaciones, Universidad de Cantabria, Plaza de la Ciencia s/n, 39005 Santander, SpainW-Band radiometers using intermediate frequency down-conversion (super-heterodyne) and direct detection are compared. Both receivers consist of two W-band low noise amplifiers and an 80-to-101 GHz filter, which conforms to the reception frequency band, in the front-end module. The back-end module of the first receiver comprises a subharmonic mixer, intermediate frequency (IF) amplification and a square-law detector. For direct detection, a W-Band detector replaces the mixer and the intermediate frequency detection stages. The performance of the whole receivers has been simulated requiring special techniques, based on data from the experimental characterization of each subsystem. In the super-heterodyne implementation a local oscillator at 27.1 GHz (with 8 dBm) with a x3 frequency multiplier is used, exhibiting an overall conversion gain around 48 dB, a noise figure around 4 dB, and an effective bandwidth over 10 GHz. In the direct detection scheme, slightly better noise performance is obtained, with a wider bandwidth, around 20 GHz, since there is no IF bandwidth limitation (~15 GHz), and even using the same 80-to-101 GHz filter, the detector can operate through the whole W-band. Moreover, W-band detector has higher sensitivity than the IF detector, increasing slightly the gain. In both cases, the receiver performance is characterized when a broadband noise input signal is applied. The radiometer characteristics have been obtained working as a total power radiometer and as a Dicke radiometer when an optical chopper is used to modulate the incoming signal. Combining this particular super-heterodyne or direct detection topologies and total power or Dicke modes of operation, four different cases are compared and discussed, achieving similar sensitivities, but better performances in terms of equivalent bandwidth and noise for the direct detection radiometer. It should be noted that this conclusion comes from a particular set of components, which we could consider as typical, but we cannot exclude other conclusions for different components, particularly for different mixers and detectors.https://www.mdpi.com/2079-9292/10/18/2317radiometersdetectorsW-band |
| spellingShingle | Juan Pablo Pascual Beatriz Aja Enrique Villa Jose Vicente Terán Luisa de la Fuente Eduardo Artal Performance Assessment of W-Band Radiometers: Direct versus Heterodyne Detections Electronics radiometers detectors W-band |
| title | Performance Assessment of W-Band Radiometers: Direct versus Heterodyne Detections |
| title_full | Performance Assessment of W-Band Radiometers: Direct versus Heterodyne Detections |
| title_fullStr | Performance Assessment of W-Band Radiometers: Direct versus Heterodyne Detections |
| title_full_unstemmed | Performance Assessment of W-Band Radiometers: Direct versus Heterodyne Detections |
| title_short | Performance Assessment of W-Band Radiometers: Direct versus Heterodyne Detections |
| title_sort | performance assessment of w band radiometers direct versus heterodyne detections |
| topic | radiometers detectors W-band |
| url | https://www.mdpi.com/2079-9292/10/18/2317 |
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