DE2355896C3 - Circuit arrangement for suppressing interference from a stabilized cavity solid-state oscillator used as a local oscillator in a radio receiving device operating according to the superimposition principle - Google Patents

Description

55 896

15 to 20 dB, uwl the noise component is passed on in the direction shown by the arrow and eliminated. Here, when the oscillator 1 is supplied directly to reception mixer 2, in which the Spiogeldem band-pass filter 8 is connected, the WIR frequency corresponding noise component P "of the oscillator kung unstable and oie control very bekompliziert via the band-stop filter 21 for the image frequency, so that the circulator 6 is generally 5 disposed; In the receiving mixer, the signal must also be provided as an isolator _: what wave f _L is mixed with the aforementioned empirical signal wave / _s entails a complicated construction, converted into the intermediate frequency signal wave

The invention is based on the task of converting this and sending it to terminal 20 as an output signal

Avoid disadvantages and removed a receiving device.

tang to create, the construction of which is simplified io When setting up the receiving mixer 2, it is

and its intermediate frequency output is highly stable and knows that the conversion loss is lowered and

is quiet. the noise factor can be improved by

This object is achieved according to the invention in that the load seen from the mixer diode is achieved by the fact that the receiving mixer is preceded by a band filter that blocks the image impedance for the image frequency and that i ₅ or short-circuiting is selected. As a means for the cavity solid-state oscillator, dispensing with the implementation of this technology, the further interposed circuit elements are generally band-stop filters which are connected to the isolator in resonance with the image frequency. is e.g. B. on one of the mixer diode by one

In the following, the invention is provided on the basis of a point which is distant at a speaking distance.

F i g. 3 shown in more detail. In this case, it is sufficient if the blocking attenuation

purifies. fo _r the image frequency is 15 dB. If a sol-

F i g. 3 shows the structure of the circuit arrangement rather mixer is used, which is above in a block diagram. The received signal wave f _s called circulator 3 to the receiving mixer 2 is from a terminal 10 via the noise component P _{m also directed in Fig} serves to let the circulator act as an isolator on the Eir.pfangsmischer 2 at the bandstop filter 21, fed to a bandpass filter 7, reflected in for the image frequency, which is at a distance corresponding to the received signal frequency of the mixer diode at a distance from the latter Bandpass filter 7 which is arranged or fed into the interior of the receiver terminal of the further circulator 3, 30 mixer is added. This noise component guided in the direction shown by the arrow, from nente P _Ni is sent to the third terminal of the circulator 3 of the third terminal and is fed to the device along the rich bandstop filter 21 shown by the arrow, which blocks the image frequency the second terminal routed and Empfangsmische- 2. on the other hand, the absorbed by the non-reflecting terminating device 15, so the cavity-controlled solid-state oscillator 1 35 that the noise factor of the reception mixer 2 source of the local oscillation signal generated wave f _L, no bad influence is exerted,
and the FM noise power P _Ns and P _m in the fre- In the above-mentioned embodiment, the frequency range corresponding to the reception frequency / _{s or the anechoic image frequency} / mirror to the circulators 4 and 5, respectively, is assigned via a third terminating device 14 and 15. However, the circulator 5 with an anechoic terminating device 15 40 can also be used instead of isolators, to the second terminal of the further circulator 3 that are sent out in the known, the first terminal and arrive at the in F i g. 1 required the aforementioned bandpass filter 7 for the received signal Hch, at the circuit frequency according to the invention. There the reception _{frequency / s} 45 arrangement is saved; Instead, the band-corresponding noise component P _{Ns of} the local barrier 21 is provided for the image frequency, which is connected to the receiver via the band-pass filter 7 of the receiver mixer 2, whereby the flexion-free terminating device 14 of the circulator 4 is not just the structure of the Circuit arrangement absorbed. The residual signal wave f _L of the simplified and the cost is reduced, and the local oscillator of the image frequency transactions / _Ppicge, 50 but also the advantages with respect to the self-noise component Corresponding P _Ni of local, such. B. substantial improvements of the generator are reflected at the band-pass filter 7, noise factor due to the introduction of the band from the first clamp of the circulator 3 along the barrier, are very large.

1 sheet of drawings

Claims (1)

Bandpass filter with a corresponding quality factor above an isolator to the output side of the oscillator Claim: is switched and the noises outside of the Circuit arrangement for the suppression of ^B ^ ^es ^ ^nt 2 _e ^{r iJi U} a ^ U) circuit diagram of an example of a Lkloszillatorver- ^B ll NR Di Disturbances from one as local oscillator- · ^B _{by ώε} reference by NR Dietrich turned, stabilized Hohlrautm Festlcorper- ~ Microwave Radio System "in" Bell System oscillator at one after the superposition !! - "j, .- Journal", Vol.50, No. 7, September 1971, principle working radio receiving device mn ^ 2175 ff. a receiver mixer, the input of which is marked with a. "^, _{d case that a} common cavity- connected to an arm of a r-circulator, an io rattung rur _eroszi , _lator ^ position generator which in 5igna | following flaßrjchtuns Anne under ges _{"matot) EXP} ends is. The reception Intermediate _shadow: from isolators, in particular ^ JJJ _{n f} ^ _{from an} antenna over a of y-circulators S ^ "connected as isolators, is connected to a terminal 10 via the solid-state cavity oscillator and the _{non-reflective Ab} Signal receiver connected and, wöbe »the 15 ^^^ 4 _that serves this circulator as an isolator in the receiver connection branch still em gjg ™? *« "_{Leave> a} bandpass filter7 in which the received signal frequency bandpass filter is connected in front of the received signal frequency in tuned to the received signal frequency is characterized overall f ™ ** ™% £ ™ _{md then} the dargekennzeichnet with arrow that the reception mixer ^ {^^ Z ^ rcn Zirkulators3 set on a (2) the image frequency (fe ^ blocking ao f ^? _we itergeleitet On the other hand, a band filter (21) is connected upstream and the -Hott · gjPj ^a g ^ _L \ _ÄatoH il «ior used cavity solid-state oscillator (l) dispensing with J» "^ solid-state oscillator 1 produced further interconnected circuit elements ^T ^^ r \ _{hsi rin} en as an insulator connected directly to the isolator (S) is turned on. issor _6, a band-pass filter 8 serving dei noises at the far away from the carrier frequency frequencies for disposal, and the cir- The invention relates to a circuit gates 5 and ^ ^ g ^^^ arrangement for suppressing interference from;. ^ Ρ. ^ώ ? * ^Γ 1 / ^ Α a stabilized 30 drive used from the local oscillator, demdieS ^ nalwellc / ^ ^S1 f ^{Solid-state cavity oscillator} at one after that of the ^D> i ⁱ f aS? ^ J ^t ^^ Ji ^ S ^ overlay principle working radio reception ^^^^^ '^ SSÄf "S5 device with a receiver mixer, whose mixer α ^ .ug ^^ .... ¹ J n-- _m icrlit and gang connected to an arm of a y-circulator who with the received signal wave /. jern'scht and is, at the following arms in the signal flow direction 35 ^dw . ^D ^ ^re ^ ^req ^ _a / vön _d er £ e "mme 20 abet with the interposition of isolators, in particular intermediate frequency signal from terminal 20 ner g, those of the F-circulators switched as isolators. PrM, ipn7he7iehunB those of the cavity solid-state oscillator and the signal In Fig. 2 * e Jrequ ^ z relationship that of fä hl id bi d Ilt im the effect of ^ Pg ^ «*? ™ _al Jn _e ? d W d ^E ^ a «eUe / d p J ^ receivers are switched, whereby the isolator in the effect of the ^ Pg ^ «*? ™ _alw Jn _e ? and Empfätfger connection branch or a dargestell the recom- 40, when the _cr ^E, X _r f ^ a "ew / and fangssigäalfrequenz tuned band pass filter upstream the signal of the Lokaloszülators WAF _L (f,> k, Zwieeschaltet is rule-frequency signal wave f _IF = Δ f - U - h) denotes ⁸ There are oscillators with a low quality factor net, the image frequency is known as J _L --Af, for which a solid-state _{oscillator- = / s} ,, e _g e. designated, undaemJ ^ uriiJ fanner akf ^ element, such as B. a Gunn diode, an IMPATT- 45 As a rule, a cavity resonator with a high 140 MHz is chosen for the intermediate frequency 70 or diode etc. _imm , _{ct #} , _{lie t} Goodness factor added and the oscillatory effect The FM noises of the cavity controlled is stabilized. By adding a hollow oscillator, up to about 10 MHz in the near space resonator with a high quality factor wkd the carrier frequency is suppressed, <because the higher «! Good stabilization of the oscillator frequency is achieved and 50 factor by adding the cavity resonator also suppresses the Noises in is reached; therefore, the above can be caused in the vicinity of the carrier frequency so that an FM noise can be kept lower than with such solid state oscillator as a source of local klystrons and frequency multipliers and as the new cheap Osalla 55 is further away, the good factor is an effective source of emission with high reliability, which instead lowers and worsens the noise characteristic. The klystrons and frequency noise components previously used in the vicinity of /, or J ₈ , ^ multiply occurs, is remarkable. However, it is J / away from the carrier frequency h , the effect of noise suppression of the solid-state is only used in the receiver mixer using the signal j _{L of} the body oscillator, in which such a stabilizing local oscillator is mixed and dropped as a noise-ms uring process on the frequencies intermediate frequency band, so that the noise factor zen is limited close to the carrier frequency, and is tert at the frequencies of the receiving mixer that are substantially less distant from the carrier frequency. In order to avoid this, the band-pass noise is still present, so that filter 8 to avoid the noise in the case of when this oscillator is e.g. Is as the distant frequencies so receiving local oscillation is used as a source to 6 _S of the carrier frequency is introduced, as shown in Fig. 1 × thereby Erdie deterioration of the noise factor of the recom- drive the reception signal wave / _s and the Spiegelfanesmischers must be avoided, by adding a frequency / _game an attenuation of at least