SU569937A1 - Device for obtaining and phase detecting of magnatic resonance signals - Google Patents

Description

This is achieved through the fact that 4) i3DBpainaiejib-Achtepuo- are introduced into the PSF / ICD device. torus, nonlinear elomeng, shnrokoyayusnyus -; low frequency cable, with the input of the gel-a1 ea-aoato | connected to the generator of the fixed frequency, and the output of the mixer, the input of the non-linear element connected with the output circuit, the power gain, and the output with the output circuit of the power output amplifier, and the output - with the input of the low frequency Ishroko-Russian one.

The drawing shows a block diagram of the proposed device. It contains a band (tunable in frequency) generator 1, a generator 2 of fixed frequency, a mixer 3, amplification 4 of the power of radio pulses, a nonlinear element 5, a broadband amplifier 6 low frequency, indicator 7 citi resonance, programming unit 8, keys 9 for generating excitation radio-JQ pulses at a fixed frequency, unit 10 for rotating the phase (phase shifter) of the exciting radio pulses, phase shifter-attenuator 11 for detecting (reference) voltage.

The high-frequency filling of the radio pulses for exciting nuclear resonance is obtained by mixing the frequencies of the generators 1 and 2 ,. Radio pulses are obtained at a fixed frequency with the help of a program block gQ 8 and keys 9, Then they enter the path of formation of exciting radio pulses, which consists of mixer 3 and power amplifier 4. Phaser 10 serves to create a specific phase shift between the high-frequency filling of the excitation radio pulses, which is necessary to realize the spin echo phase methods. A detecting (reference) voltage for phase detection is also obtained as a result of mixing; frequency from oscillators 1 and 2. The required phase shift between the resonance signal and the detecting signal is created by the phase shifter 11, For that; TH, in order to create the optimum ratio of the 44 amplitudes of the signal that occurs in the sample placed in the output coil. The amplifier 4 of the power and reference voltage when detected by the nonlinear element 5, the block 11 must also perform the IO function, Wideband force, 6 serves to enhance the detected nth sparse resonance at low frequency. ..For a superb 1 day signal, the iidicate serves})) 7, J5

V11Is:; | H1 ok; ilrpanthe at working ri ri; ii; ji, n orpx 1 and 2 re; i; o; imu.-p.sam) in Kaiocr-RO

four

in the range generator) p can be with a monopoly frequency synthesizer, Egch) aaAaRJiiunI i.irator use a pda as a gonetor 2 of a fixed frequency, as well as for a pulse program.

The tuning of a powerful Koiriypa power amplifier 4 with a change in the frequency of a s, and an ad- ering generator can be degraded, for example, with the help of an automatic tracking system P) I to the maximum of high-frequency power in the circuit.

 transient magnetic resonance signals (induction or spin echo) are determined by the filling phases of the excited radio pulses. The phase filling between the radio pulses in the above flowchart is set by the phase shift at a fixed frequency and does not change with a change in the frequency of the oscillator generator 1, in other words, the phase shift of the radio frequency 3, the excitation line and the pulses remain with the filling frequency. In order to keep the phase constant between the transient signal and the detecting reference voltage when changing the filling frequency (to enable optimal phase detection at different resonant frequencies), it is sufficient to ensure a constant phase shift between the detecting voltage and the filling of the exciting radio pulses. In the proposed device, this is achieved by introducing a voltage of a fixed frequency through a separate channel, in which the phase can be rotated by the required angle for optimum detection, into the formation of the excitation radio pulses (L xy

3 and 4),

To eliminate any tweaked

receiver resonance signals (blocks 5, .6.7, phase-coherent detection is carried out directly after the power amplifier on the nonlinear element 5 and the main signal amplification is made by a low-frequency 1M amplifier 6 low frequency;; To save the entire power of the resonant signal, it is sufficient to have a band of about 100 kHz.

Claims (1)

Direct gain frequency receivers can also be used, since the relative phase shift between the reference voltage and the usb voltage as it passes simultaneously in the receiving path remains unchanged (the frequency of the signal and the reference voltage is the same). i) iHi} OKi loudspeaker amplifier with h ((P1, corresponding to the non-sync repoise, k, output ctg) p (1I) d1M1 optical n1111 element 1 component. The device allows you to search) to search for and compare the spectra of beacon tuning a, and at the phase of detonation, the preservation of the eo pooooooled phase shift between the NMR and NQR line and the detecting (reference) crib, which ensures the optimal phase detection of the tin trans rasalichny resonant frequencies ,. Apparatus of the Invention A device for receiving and phase detection of magnetic resonance signals containing a band generator, a generator (fixed frequency torus, mixer, power amplifier of radio pulses, a programming unit, shaping keys and a phase generator of radio frequency pulses at a fixed frequency, characterized in that to increase the sensitivity of the search for unknown spectra, a phase shifter-attenuator, a nonlinear element, a broadband low-frequency amplifier, and an input The rotator - the attenuator is connected to a fixed frequency generator, and the output is connected to the mixer input, the input of the nonlinear element is connected to the output circuit of the power amplifier, and the output is connected to the input of the wideband low frequency amplifier, Exterior information taken during examination 1.Patent US No. 3474328, CL 3-01N 27/78, 1971, 2, USSR Copyright Certificate hfe 309322, CL ,, 01 g 33/00, 1970,