| Method for solving two rf signals' angular position -> Monitor Keywords |
|
|
 
Method for solving two rf signals' angular positionMethod for solving two rf signals' angular position description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20080030397, Method for solving two rf signals' angular position. Brief Patent Description - Full Patent Description - Patent Application Claims
BACKGROUND OF THE INVENTION [0001]1. Field of the Invention [0002]The present invention relates generally to radar used for tracking multiple targets. More specifically, the present invention relates to a method for solving for the angular position of two RF (radio frequency) signals. [0003]2. Description of the Prior Art [0004]Currently, military tracking radar is widely used to track targets and threats, such as enemy aircraft because of its high degree of accuracy and relative immunity to electronic countermeasures that can degrade tracking radar and their associated methods of tracking. Generally military tracking radar uses a single RF pulse to gather angle information, as opposed to directing multiple narrow-beam pulses in different directions and looking for a maximum return to identify the target. [0005]When there are two targets being tracked by radar, two RF signals at different frequencies are generated. The two RF signals produce a beat pattern in power return, with beats occurring at the frequency difference between the two RF signals. This beat pattern is produced by adding the RF signals and then subtracting the RF signals. [0006]With current angle processing techniques utilized to pull out the angle of the combined RF signal, the non-linearity of the processing technique ensures that for a difference greater than five percent between the powers of each signal, the angle as averaged over a beat period is almost entirely captured by the dominant of the two RF signals. [0007]Currently utilized angle processing techniques use averaging to pull out the dominant signal. For those cases where two RF signals are changing in power return such that the two RF signals are alternating as to which one of the two signals is dominant, there is need for signal processing techniques to recognize when one signal's angle is appearing as opposed to the other signal's angle is appearing. This requirement necessitates that the angles for the two RF signals be sorted in time. [0008]Further, since only one of the two RF signals is visible during any given time period, two types of adverse situations can occur with present angle processing techniques. First, the RF signal being analyzed can be dominated by the other RF signal during a critical time period, such that the RF signal information is being extrapolated. Second, the sorting of each RF signal can be confused by environmental angle disturbances. [0009]Accordingly, angle processing would be substantially improved if both RF signals' angles are calculated simultaneously, even when one RF signal dominates the other of the two RF signals. SUMMARY OF THE INVENTION [0010]The present invention overcomes some of the difficulties of the past including those mentioned above in that the present invention provides for a relatively simple yet highly effective method for determining the angular position of two RF signals from the dominant RF signals power return data. [0011]The method comprising the present invention requires the step of providing an angle voltage centroid between the two RF signals by a determination of an angle during peaks in power return. The method then requires the step of providing the dominant RF signal's angle which is determined by the average composite angle over the frequency difference period. The method also requires the step of providing the two RF signal voltages which are determined from peak and minimum power values. The step of calculating the smaller RF signals voltage is found from the values obtained for the angle voltage centroid for the two RF signals, the dominant RF signal's angle, and the two RF signal's voltages. [0012]Thus, utilizing the method of the present invention, both RF signals' angles can be calculated simultaneously, even though one RF signal may be dominated by the other RF signal. BRIEF DESCRIPTION OF THE DRAWINGS [0013]FIG. 1 are plots which illustrates a dominant RF signal's angle, a smaller signal's RF angle and a composite angle obtained by adding the two RF signals over a period; [0014]FIG. 2 is a composite plot which illustrates a composite power for the two RF signals of FIG. 1 over a period; [0015]FIG. 3 is a period-averaged composite angle plot which illustrates an average of the composite angle for the two RF signals of FIG. 1 over a period; and [0016]FIGS. 4-7 illustrate a pair of examples of two RF signals' signals added together and the resultant composite signal. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT [0017]Referring first to FIGS. 1, 2 and 3, FIG. 1 shows an angle plot for two RF signals over time which includes a composite angle obtained by adding two RF signals together. The plot identified by the reference numeral 20 is the composite angle for the two RF signals. The plot identified by the reference numeral 22 is the dominant RF signal's angle. The plot identified by the reference numeral 24 is the smaller RF signal's angle. FIG. 2 illustrates a composite power plot, identified by the reference numeral 26, for the RF signals over time. [0018]FIG. 3 illustrates a period-averaged composite angle plot, identified by the reference 28, for the composite angle of the two RF signals over time. The period-averaged composite angle 28 of FIG. 3 is the dominant signal's angle over the time period of approximately one second and has a value of -0.15 degrees. It should be noted that the average of the period-averaged composite angle 28 of FIG. 3 is the same as the dominant signal's angle 22 of FIG. 2. [0019]In addition to the average over the frequency difference period providing the dominant signal's angle (for signals with at least a 5% difference in power return), the angle during peaks in power return provides an angle voltage centroid between the two RF signals. For the example illustrated in FIGS. 1-3, the angle at peak power, identified by the reference 30 in FIG. 1 is -0.034 (FIG. 1) for a 1.9751 volt RF signal at -0.1511 degrees and a 0.9605 volt RF signal at 0.2027 degrees. [0020]The centroid is determined using the following expression: Continue reading about Method for solving two rf signals' angular position... Full patent description for Method for solving two rf signals' angular position Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Method for solving two rf signals' angular position patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Method for solving two rf signals' angular position or other areas of interest. ### Previous Patent Application: Single bit pseudomonopulse tracking system for frequency agile receivers Next Patent Application: Monitor Industry Class: Communications: directive radio wave systems and devices (e.g., radar, radio navigation) ### FreshPatents.com Support Thank you for viewing the Method for solving two rf signals' angular position patent info. IP-related news and info Results in 0.54133 seconds Other interesting Feshpatents.com categories: Accenture , Agouron Pharmaceuticals , Amgen , AT&T , Bausch & Lomb , Callaway Golf 174 |
 * Protect your Inventions * US Patent Office filing 
PATENT INFO |
|
