Upper LO (24.8 to 34.3 GHz) Problems

  • This section is intended as a reference page to document and understand the problems with the upper LO design.

  • Note: The Hittie Mulitplier HMC 578 in combination with a WR-42 waveguide filter, and a MCLI PS8-54 combination successfully supplies the upper LO for the TYPE I and II downconverters.

Wilkinson Two Way Divider Circuit.

  • Below, Single two-way power divider assembly in a test fixture, 24.8 - 34.3 Ghz,
  • Shown with 3dB attenuators, short alumina lines, and profiled top cover
  • Cavity dimensions, cover off: 0.67 wide x 1.02 long x 0.24 deep (inches)
  • Photo by Bill Saxton
    HF pwrdiv assy.jpg

  • Below, Single two-way power divider in a test fixture, 24.8 - 34.3 Ghz,
  • Divider only, with profiled top cover. Without attenuators or short alumina microstrip lines
  • Cavity dimensions, cover off: 0.48 wide x 1.02 long x 0.24 deep (inches)
  • Photo by Bill Saxton
    HF pwrdiv.jpg

  • POWER DIVIDER MODELING RESULTS:

  • ShortWilkin_time_cover_K.bmp: Wilkinson Divider CST transient analysis with cover and K connectors.(Note: convergence problems, TS replaces Nichrome Ohmic sheet with PEC).

  • POWER DIVIDER TEST RESULTS:

  • MCLI PS8-54 (purchased) POWER DIVIDER TEST RESULTS:

Quartz Edge Coupled Filter (Bandpass)

  • Below, Quartz filter test fixture shown with profiled top cover, 24.8 - 34.3 Ghz,
  • Cavity dimensions, cover off: 0.44 wide x 1.54 long x 0.24 deep (inches)
  • Photo by Bill Saxton :
    quartz filt A.jpg

  • Below, Close-up of quartz filter test fixture, 24.8 - 34.3 Ghz, Photo by Bill Saxton:
  • Cavity dimensions, cover off: 0.44 wide x 1.54 long x 0.24 deep (inches)
  • Photo by Bill Saxton :
    quart filt B.jpg

  • QUARTZ FILTER MODELING RESULTS:

  • The discrepancy between the CST model and MWO model is primarily the effect of the tapered quartz transition between the 50 Ohm line (25 mils) and the 9.4 mil alumina line. The MWO office model suggests a better S11 and S21 performance than measured. This model did not include the tapered transition with only the 50 Ohm line as input (Model M1). Once the taper is included(Model M2), the match tends to agree with the CST models and the measured results. Several various CST models were executed in an attempt to simulate the measured results. The quartz filter without the K connector beads in both a closed and open cavity, Models C1 and C2, respectively. The quartz filter in an open cavity with K connector beads, Model C3. The quartz filter without the alumina transitions, but with the quartz transitions with K connectors in a closed and open cavity, Model C4 and C5, respectively. And finally a CST model without the quartz and alumina transitions and without the vias in to compare the MWO models and CST models(C6,C7,C8).

  • CONCLUSION
    • The quartz CPW transitions did not provide adequate impedance match. The model C6-8 of the scribed and broken substrate indicate an improvement, although the wider bandwidth differs from the MWO model, M3.
    • CST models predict better than -10 dB return loss with no CPW transition. Either a spark plug K connector transition (Matt Morgan's design) or a straight thru connection should work, although the straight thru is much more dependent upon machining. Both types were modeled giving similar results. Addition of the Corning glass 7070 bead with an air line coax between the bead and microstrip line degrade the return loss by 10 dB.
    • 403arch_nobead.bmp: CST (TS) model of spark plug transition without glass bead.
    • 403arch_bead.bmp: CST (TS) model of spark plug transition with glass bead.
    • 403arch_bead_CPW_10Al.bmp: CST (TS) model of spark plug transition with glass bead, CPW transition, and 10 mil Alumina microstrip line.

    • More evidence to support poor match from transitions. Measured data from one section with narrow bandwidth design: Note the mismatch at 32 GHz and dip in S21 response.

  • CST MODEL

  • Model C1 QuartzFil_K_V_closed.bmp: CST model(transient solver) with closed cavity, no K connectors, alumina transitions present

  • Model C2 QuartzFil_nK_V.bmp: CST model(transient solver) with open cavity, no K connectors, alumina transitions present.

  • Model C3 QuartzFil_K_V.bmp:CST model(transient solver) with open cavity, with K connectors, alumina transitions present.

  • Model C4 QuartzFil.bmp: CST model(transient solver) with closed cavity, with K connectors, no alumina transitions.

  • Model C5 QuartzFil_open.bmp: CST model(transient solver) with open cavity, with K connectors, no alumina transitions.

  • Microwave Office MODEL

  • Model M1: Cascade.pdf: Microwave Office Model updated April 13, 2010; no tapered transitions and no vias.

  • Model M2: Quartz_Filter_MWO.pdf: Microwave Office Model updated April 13, 2010; with tapered quartz transitions and vias.

  • QUARTZ FILTER TEST RESULTS:

  • WgFilter.pdf: Ka-band waveguide high-pass filter for reference

_Lower LO (8.9 GHz) Documentation_

  • 8900 Mhz LO amplifier test fixture, Photo by Bill Saxton
  • Amplifier based on Hittite HMC451
    8900 amp.jpg

  • 8900 Mhz AMPLIFIER TEST RESULTS:

Original schedule

Topic attachments
I Attachment Action Size Date Who Comment
403arch_bead.bmpbmp 403arch_bead.bmp manage 1 MB 2010-05-06 - 09:55 StevenWhite  
403arch_bead_CPW_10Al.bmpbmp 403arch_bead_CPW_10Al.bmp manage 1 MB 2010-05-06 - 09:55 StevenWhite  
403arch_nobead.bmpbmp 403arch_nobead.bmp manage 1 MB 2010-05-06 - 09:55 StevenWhite  
8900_amp.pdfpdf 8900_amp.pdf manage 78 K 2010-04-01 - 11:37 BobSimon 8900
8way_div.pdfpdf 8way_div.pdf manage 90 K 2010-04-01 - 09:58 BobSimon 8way
8way_div_spec.pdfpdf 8way_div_spec.pdf manage 131 K 2010-04-01 - 09:50 BobSimon mcli
Cascade.pdfpdf Cascade.pdf manage 12 K 2010-04-13 - 08:52 StevenWhite  
Filter_Response_w_CPW.pdfpdf Filter_Response_w_CPW.pdf manage 12 K 2010-04-15 - 11:14 StevenWhite  
KFPASchedule.mppmpp KFPASchedule.mpp manage 240 K 2009-03-06 - 08:12 UnknownUser  
MWO_Shorten_Substrate.pdfpdf MWO_Shorten_Substrate.pdf manage 12 K 2010-04-14 - 11:19 StevenWhite  
PowerDivider_noK.bmpbmp PowerDivider_noK.bmp manage 1 MB 2010-04-14 - 12:41 StevenWhite  
QU_freq_nK_nV_short_S11.bmpbmp QU_freq_nK_nV_short_S11.bmp manage 1 MB 2010-04-14 - 11:03 StevenWhite  
QU_freq_nK_nV_short_S21.bmpbmp QU_freq_nK_nV_short_S21.bmp manage 1 MB 2010-04-14 - 11:03 StevenWhite  
QU_freq_nK_nV_short_S21_MAG.bmpbmp QU_freq_nK_nV_short_S21_MAG.bmp manage 1 MB 2010-04-14 - 11:03 StevenWhite  
QuartzFil.bmpbmp QuartzFil.bmp manage 1 MB 2010-03-31 - 08:48 StevenWhite  
QuartzFil_K_V.bmpbmp QuartzFil_K_V.bmp manage 1 MB 2010-04-13 - 16:23 StevenWhite  
QuartzFil_K_V_closed.bmpbmp QuartzFil_K_V_closed.bmp manage 1 MB 2010-04-13 - 16:48 StevenWhite  
QuartzFil_MWO.pdfpdf QuartzFil_MWO.pdf manage 10 K 2010-04-13 - 16:35 StevenWhite  
QuartzFil_NT.bmpbmp QuartzFil_NT.bmp manage 1 MB 2010-04-14 - 09:01 StevenWhite  
QuartzFil_nK_V.bmpbmp QuartzFil_nK_V.bmp manage 1 MB 2010-04-13 - 16:23 StevenWhite  
QuartzFil_open.bmpbmp QuartzFil_open.bmp manage 1 MB 2010-03-31 - 08:49 StevenWhite  
Quartz_Filter_MWO.pdfpdf Quartz_Filter_MWO.pdf manage 12 K 2010-04-13 - 16:46 StevenWhite  
Quartz_noCPW_S21.pdfpdf Quartz_noCPW_S21.pdf manage 134 K 2010-07-20 - 09:29 StevenWhite  
Quartz_short_CST.pdfpdf Quartz_short_CST.pdf manage 62 K 2010-04-26 - 15:11 StevenWhite  
Quartz_short_S11.pdfpdf Quartz_short_S11.pdf manage 67 K 2010-04-26 - 15:11 StevenWhite  
Quartz_short_S21.pdfpdf Quartz_short_S21.pdf manage 69 K 2010-04-26 - 15:11 StevenWhite  
ShortWIlken_KConn.bmpbmp ShortWIlken_KConn.bmp manage 1 MB 2010-03-31 - 10:20 StevenWhite  
ShortWilken_time_cover_K.bmpbmp ShortWilken_time_cover_K.bmp manage 1 MB 2010-04-01 - 09:59 StevenWhite  
ShortWilken_time_nocover_K.bmpbmp ShortWilken_time_nocover_K.bmp manage 1 MB 2010-04-01 - 10:00 StevenWhite  
Upper_LO_Distribution.docxdocx Upper_LO_Distribution.docx manage 12 K 2010-04-01 - 09:54 StevenWhite  
Wilen_only_MMlaunch.pdfpdf Wilen_only_MMlaunch.pdf manage 157 K 2010-07-20 - 09:21 StevenWhite  
Wilen_only_MMlaunch_iso.pdfpdf Wilen_only_MMlaunch_iso.pdf manage 151 K 2010-07-20 - 09:25 StevenWhite  
Wilk_split_FS_Kconn.bmpbmp Wilk_split_FS_Kconn.bmp manage 1 MB 2010-07-21 - 09:32 StevenWhite  
Wilk_split_FS_Matt_X.bmpbmp Wilk_split_FS_Matt_X.bmp manage 1 MB 2010-07-21 - 09:33 StevenWhite  
WilkenSplitter.pdfpdf WilkenSplitter.pdf manage 12 K 2010-03-31 - 11:16 StevenWhite  
kfpa_LO.docxdocx kfpa_LO.docx manage 13 K 2010-04-01 - 13:13 BobSimon doc
pwr-div_only.pdfpdf pwr-div_only.pdf manage 90 K 2010-04-01 - 11:42 BobSimon pwr
pwr-div_only_cover_on.pdfpdf pwr-div_only_cover_on.pdf manage 80 K 2010-04-01 - 11:46 BobSimon asdf
pwr_div_assem.pdfpdf pwr_div_assem.pdf manage 96 K 2010-04-01 - 09:32 BobSimon pwr div assembly
pwr_s22.pdfpdf pwr_s22.pdf manage 86 K 2010-04-01 - 11:48 BobSimon asdf
quartz_filt_A.jpgjpg quartz_filt_A.jpg manage 30 K 2010-04-01 - 08:15 BobSimon Quartz filter
quartz_filter.pdfpdf quartz_filter.pdf manage 139 K 2010-04-01 - 09:26 BobSimon quartz
wg_filter.pdfpdf wg_filter.pdf manage 84 K 2010-04-01 - 13:25 BobSimon WGASDF
Topic revision: r37 - 2010-07-21, StevenWhite
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