Email Detail

HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/WD2R6OC5V3GC6FYBJWMTSBDISEKWCC5K/?format=api",
    "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api",
    "message_id": "[email protected]",
    "message_id_hash": "WD2R6OC5V3GC6FYBJWMTSBDISEKWCC5K",
    "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/KK75DA42V2CVIKOT3KCXESRATCF6E3X2/?format=api",
    "sender": {
        "address": "bill (a) hsmicrowave.com",
        "mailman_id": "d7ecbf0c1df148f289f27dd7a8c37974",
        "emails": "https://mailman.amsat.org/hyperkitty/api/sender/d7ecbf0c1df148f289f27dd7a8c37974/emails/?format=api"
    },
    "sender_name": "Bill Ress",
    "subject": "[eagle]  Some Phase Noise Numbers!!",
    "date": "2007-06-11T06:10:47Z",
    "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/3NQYJ7OLJMRQFOFSNI6DMKUTFUZQS3UH/?format=api",
    "children": [],
    "votes": {
        "likes": 0,
        "dislikes": 0,
        "status": "neutral"
    },
    "content": "Jim,\n\nTo help with your question, some good phase noise numbers to ponder are \nas follows:\n\nUsing direct synthesis techniques (multiply/mix/divide and not using any \nPLLs or VCO's - this would be like the Comstron and PTS series of \nsynthesizers), which use a low noise 10 MHz reference and will provide \nphase noise performance as follows:\n\n600 MHz - -138 dBc/Hz at 10 KHz offset\n1.2 GHz - 132 dBc/Hz at 10 KHz\nand following the 6 dB increase each time the frequency is doubled, -114 \ndBc/Hz at 10 KHz at 9.2 GHz.\n\nA very low noise VHF crystal controlled oscillator/multiplier designed \nfor a X-Band military doppler RADAR will do -118 to -124 dBc/Hz at 10 KHz.\n\nI have seen -132 dBC/Hz at 10 KHz at X-Band in the laboratory using a \nfundamental mode cylindrical cavity oscillator (about the size of a \ncoffee can). That's close to the ultimate low noise X-Band source - the \ndouble cavity klystron. Some chaps in Australia are doing about that \nwith something called a smaller whisper mode cavity - if memory serves \nme right.\n\nA really good free running transistor, not FET, DRO at X-Band will do \nabout 85 to 90 dBc/Hz at 10 KHz. The FET DRO will be 10 to 15 dB worse.\n\nThe point I'm trying to make is that these numbers are obtained with \nconsiderable pain (complexity and size). So to get -110 dBC/Hz at 10 KHz \nat C Band for instance, you'll have to resort to a sophisticated low \nnoise VHF crystal oscillator locked to a low noise 10 MHz oscillator and \nthen multiplied to C band using pretty tight filtering along the way to \nreduced the spurious to less than -60 dB. Not exactly your straight \nforward PLL IC chip and a good dielectric resonator VCO.\n\nNow if you ask what phase noise and at what distance from the carrier is \nrequired for a particular modulation format, then those numbers can \nbecome a little more argumentative since many variable factors enter \ninto the equation. It can also matter if the signal is used as a \nreceiver LO or a transmitter LO.\n\nNow finally - - - for my opinion about your question for what do you \nneed for X band terrestrial narrow band work, it appears to me that most \nX-Band EME is done with LO's running around -90 to -110 dBc/Hz at 10 KHz \nwhich is what the typical CMI or Frequency West phase locked cavity \noscillator/multipliers will do but I'm convinced even -70 dBc to -80 \ndBc/Hz at 10 KHz. (or even worse) will also work. More important, for CW \nand SSB, what is the phase noise at 0.5 to 4 KHz.\n\nAs a point of note, the phase noise functional specifications for the \nJPL Mars Reconnaissance Orbiter SDST (Small Deep Space Transponder) \nreceiver and exciter are ≤ −20 dBc/Hz at 1 Hz, ≤ −60 dBc/Hz at 100–1000 \nHz, and ≤ −70 dBc/Hz at 1–100 kHz.\n\nWell hopefully - - - the satellite system guys have our required numbers \nfigured out and will be sharing them with us sub-system component guys \nreal soon!!!\n\nJim Sanford wrote:\n> Bill:\n> -110 dbc/hz at 10khz offset is what I REMEMBER in my response to the \n> question, \"What is a good phase noise number to shoot for in a \n> microwave narrowband (ssb/cw) system?\"\n> My memory may very well be WRONG, which was the point of asking my \n> question.\n>\n> I agree with you, looks like -90dbC at 10 KHz, but given what Juan's \n> already said about his sources, and the uncertainties of the SDR-IQ, \n> that may be VERY good!\n>\n> Do you have a different answer to my original question, \"What is a \n> good phase noise number to shoot for in a microwave narrowband \n> (ssb/cw) system?\" If so, I'd like to engage in that conversation, both \n> for Eagle and for my terrestrial microwave station.\n>\n> I agree with your assessment of Juan's work -- ABSOLUTELY EXEMPLARY!!!!!!\n>\n> Thanks & 73,\n> Jim\n> [email protected]\n>\n>\n> Bill Ress wrote:\n>\n>> Jim,\n>>\n>> Where did the -110 dBC/Hz at 10 KHz come from? And at what frequency? \n>> That's pretty aggressive using straight forward VCO's and PLLs. From \n>> Juan's data with his snappy SDRIQ, it looks like that the 70 cm is \n>> doing about -90 dBc/Hz at10 KHz. I thought that's what I read from \n>> his early HP8566B dtata.\n>>\n>> My straight forward S2 RX downconverter PLL LO does -100 dBc/Hz at 10 \n>> KHz.\n>>\n>> We'd better get a good read on this since, if real, it forces more \n>> sophisticated LO designs.\n>>\n>> Great work Juan!!\n>>\n>> Regards...Bill - N6GHz\n>>\n>>\n>>\n>> Jim Sanford wrote:\n>>\n>>>\n>>> I think I remember Bob's answer as -110dbc at 10 KHz offset.\n>>>\n>>> Thanks & 73,\n>>> Jim\n>>> [email protected]\n>>\n>>\n>>\n>\n>\n\n",
    "attachments": []
}